diff --git a/PROJECT_STATE.md b/PROJECT_STATE.md
index c3b179d8..3cad6963 100644
--- a/PROJECT_STATE.md
+++ b/PROJECT_STATE.md
@@ -1,6 +1,6 @@
 # ThothII — Project State
 
-> Starting-point snapshot for new sessions. Last updated: 2026-08-08 (Task 13 verification audit).
+> Starting-point snapshot for new sessions. Last updated: 2026-08-08 (final review fix round 1).
 > Point a fresh session here ("read PROJECT_STATE.md") before substantial work.
 
 ## Internal Qdrant + Ollama semantic infrastructure — LIVE 2026-08-08
@@ -14,6 +14,12 @@
 - **Semantic contract.** Internal semantic indexing is fixed to `qwen3-embedding:0.6b`,
   `1024` dimensions, and cosine distance. Schema-v3 descriptors are operational; schema-v1/v2 descriptors remain `migration_required` until an explicit reviewed migration writes schema version 3. One workspace owns one Qdrant collection, and schema, Evidence, and Memory records
   coexist inside that collection with payload `kind` separation.
+- **Final review runtime barriers.** Operational routes, retained session pins, and runtime
+  rendering now require schema version 3 before resolving bindings, readiness, diagnostics, or
+  Pi. Session admission verifies the exact internal Qdrant collection (dimensions, cosine
+  distance, and required keyword payload indexes) before Ollama and before manifest persistence.
+  The Qdrant adapter binds every search/list/delete filter to its constructed workspace identity
+  and rejects conflicting caller namespaces.
 - **Boundary and persistence.** Only DWH and LLM remain external runtime application endpoints.
   There are no active external vector or embedding endpoint instructions, bindings, or secrets in
   the supported operator manuals. Qdrant remains a derived but persistent semantic index: the
@@ -26,7 +32,9 @@
   --confirm-project <name>` requires the exact repeated project confirmation, validates manifest
   and archive safety before stopping `qdrant`, stages rollback content, restores in place, and
   restarts `qdrant` only if it was previously running. Restore does not migrate legacy workspace
-  descriptors, rename collections, or repair a semantic-index incompatibility.
+  descriptors, rename collections, or repair a semantic-index incompatibility. Backup and restore
+  share one atomic Docker-daemon lock per Compose project/Qdrant volume; contenders fail before
+  volume resolution, and cleanup removes the lock only when its ownership labels still match.
 - **Verification recorded for Task 13 final audit.** On Apple M4 Pro
   (`Darwin 25.5.0`, Docker Server `29.6.2 linux/arm64`), harness pytest passed
   **819 passed / 4 deselected**; backend Vitest passed **464/464** plus TypeScript and build;
@@ -59,6 +67,14 @@
   SQL, L2 legacy fixtures, gitignored task notes, and historical reference notes. No active
   schema-v3 operator manual or supported runtime deployment path retains external vector or
   embedding endpoint coupling.
+- **Final review fix verification.** Backend Vitest passed **477/477** plus TypeScript and build;
+  harness pytest passed **824 passed / 4 deselected** with the existing 74 warnings; touched Python
+  files are Ruff-clean. The deterministic backup/restore safety test proves lock ownership,
+  backup–backup and backup–restore contention, rollback, and cleanup. Internal semantic Compose
+  and no-deployment-coupling contracts pass. A fresh one-shot unified deployment smoke reached its
+  pre-existing `thothctl` bad-candidate rollback scenario and failed there before backup/restore;
+  its exact resource-cleanup proof passed, so this run is recorded as a limitation, not as a
+  successful revalidation of the earlier Task 13 unified-smoke result.
 
 ## Historical snapshots and archived reference notes
 
diff --git a/backend/src/routes/sessions.ts b/backend/src/routes/sessions.ts
index 785473e2..d0da061b 100644
--- a/backend/src/routes/sessions.ts
+++ b/backend/src/routes/sessions.ts
@@ -8,7 +8,7 @@ import type { PrincipalContext } from "../auth/principal.js";
 import type { ReadinessManager } from "../runtime/readiness-manager.js";
 import type { ListModelsFn } from "./meta.js";
 import type { WorkspaceRegistry } from "../workspaces/registry.js";
-import type { WorkspaceDescriptor } from "../workspaces/schema.js";
+import { validateOperationalWorkspace, type WorkspaceDescriptor } from "../workspaces/schema.js";
 import type { MaintenanceBarrier } from "../runtime/maintenance-gate.js";
 
 const BOOTSTRAP_FAILURE_MESSAGE =
@@ -108,7 +108,11 @@ export function sessionRoutes(
   const isNotFound = (error: unknown) =>
     /not found|non trovata|inesistente|404/i.test(error instanceof Error ? error.message : String(error));
 
-  type LocatedSession = { manifest: any; workspaceConfigPath: string };
+  type LocatedSession = {
+    manifest: any;
+    workspaceConfigPath: string;
+    workspace?: WorkspaceDescriptor;
+  };
 
   const workspaceRevisionUnavailable = () => Object.assign(
     new Error("workspace revision unavailable"), { code: "workspace_revision_unavailable" },
@@ -168,7 +172,12 @@ export function sessionRoutes(
     if (!saved.workspace_id || !saved.workspace_revision) return located;
     try {
       const pinned = await d.workspaceRegistry.readPinned(saved.workspace_id, saved.workspace_revision);
-      return { ...located, workspaceConfigPath: pinned.workspaceConfigPath ?? (pinned as any).revision?.snapshotPath };
+      const workspace = validateOperationalWorkspace(pinned.workspace);
+      return {
+        ...located,
+        workspace,
+        workspaceConfigPath: pinned.workspaceConfigPath ?? (pinned as any).revision?.snapshotPath,
+      };
     } catch {
       throw workspaceRevisionUnavailable();
     }
@@ -319,6 +328,7 @@ export function sessionRoutes(
       let workspaceConfigPath: string | undefined;
       let workspaceId: string | undefined;
       let workspaceRevision: string | undefined;
+      let workspaceDescriptor: WorkspaceDescriptor | undefined;
       let allowedModels: readonly string[] | undefined;
       if (requestedWorkspaceId) {
         try {
@@ -344,6 +354,7 @@ export function sessionRoutes(
           workspaceConfigPath = resolved.revision.snapshotPath;
           workspaceId = resolved.revision.id;
           workspaceRevision = resolved.revision.commit;
+          workspaceDescriptor = resolved.workspace;
           allowedModels = resolved.workspace.llm_policy.allowed;
         } catch {
           return reply.code(409).send({
@@ -362,8 +373,13 @@ export function sessionRoutes(
       // runtime owned by this principal, while runtimes belonging to other users remain intact.
       // Optional chaining preserves the deliberately narrow manager stubs used by route tests.
       for (const id of d.mgr.teardownForPrincipal?.(principal) ?? []) boundRuntimes.delete(id);
-      const ensure = await d.readiness.ensure(workspaceConfigPath ?? "", principal);
-      if (!ensure.ok) return reply.code(503).send({ error: READINESS_FAILURE_MESSAGE });
+      const ensure = await d.readiness.ensure(
+        workspaceConfigPath ?? "", principal, workspaceDescriptor,
+      );
+      if (!ensure.ok) return reply.code(503).send({
+        error: READINESS_FAILURE_MESSAGE,
+        ...(ensure.code ? { code: ensure.code } : {}),
+      });
       // Local-only: verify the DWH is reachable BEFORE creating the session, so a dropped
       // VPN surfaces as an up-front alert instead of a session that spawns Pi and then dies
       // in bootstrap retrieval. `code` lets the client show a specific message.
@@ -546,7 +562,12 @@ export function sessionRoutes(
         workspace_id?: string; workspace_revision?: string;
       };
       let workspaceConfigPath: string;
-      try { workspaceConfigPath = (await resolveSessionWorkspace(located)).workspaceConfigPath; }
+      let workspaceDescriptor: WorkspaceDescriptor | undefined;
+      try {
+        const resolved = await resolveSessionWorkspace(located);
+        workspaceConfigPath = resolved.workspaceConfigPath;
+        workspaceDescriptor = resolved.workspace;
+      }
       catch { return unavailableWorkspaceReply(reply); }
       try { settings = await d.getSettings(principal); } catch { return storageFailure(reply); }
       // This check belongs inside the per-session lock: a preceding cold Resume may have
@@ -558,8 +579,13 @@ export function sessionRoutes(
           return reply.code(200).send({ id, alreadyActive: true });
         }
       }
-      const ensure = await d.readiness.ensure(workspaceConfigPath ?? "", principal);
-      if (!ensure.ok) return reply.code(503).send({ error: READINESS_FAILURE_MESSAGE });
+      const ensure = await d.readiness.ensure(
+        workspaceConfigPath ?? "", principal, workspaceDescriptor,
+      );
+      if (!ensure.ok) return reply.code(503).send({
+        error: READINESS_FAILURE_MESSAGE,
+        ...(ensure.code ? { code: ensure.code } : {}),
+      });
       const options = {
         provider: saved?.provider,
         model: saved?.model,
diff --git a/backend/src/routes/workspaces.ts b/backend/src/routes/workspaces.ts
index 5f727fd4..3ce75baa 100644
--- a/backend/src/routes/workspaces.ts
+++ b/backend/src/routes/workspaces.ts
@@ -19,6 +19,7 @@ import {
   parseWorkspaceYaml,
   serializeWorkspaceYaml,
   validateCanonicalWorkspace,
+  validateOperationalWorkspace,
   type CanonicalWorkspace,
   type WorkspaceDescriptor,
 } from "../workspaces/schema.js";
@@ -327,9 +328,22 @@ export function workspaceRoutes(app: FastifyInstance, deps: WorkspaceRoutesDeps)
   app.post("/workspaces/:id/test", async (request, reply) => {
     try {
       const { id } = z.object({ id: workspaceId }).parse(request.params);
-      const { workspace } = await deps.registry.read(id);
-      const bindings = resolveRuntimeBindings(workspace, process.env, deps.config.secretRoots);
-      return await deps.diagnose(workspace, bindings, { writeProbe: false });
+      const { workspace, revision } = await deps.registry.read(id);
+      if (revision.state !== "operational") {
+        throw new WorkspaceRegistryError(
+          "workspace_not_activatable", "Workspace requires explicit migration",
+        );
+      }
+      let operational: CanonicalWorkspace;
+      try {
+        operational = validateOperationalWorkspace(workspace);
+      } catch {
+        throw new WorkspaceRegistryError(
+          "workspace_not_activatable", "Workspace requires explicit migration",
+        );
+      }
+      const bindings = resolveRuntimeBindings(operational, process.env, deps.config.secretRoots);
+      return await deps.diagnose(operational, bindings, { writeProbe: false });
     } catch (error) {
       return errorReply(reply, error);
     }
diff --git a/backend/src/runtime/readiness-manager.ts b/backend/src/runtime/readiness-manager.ts
index 1c49494e..2b0963f0 100644
--- a/backend/src/runtime/readiness-manager.ts
+++ b/backend/src/runtime/readiness-manager.ts
@@ -1,9 +1,16 @@
-import type { OllamaEnsureResult, ThtRunner } from "../tht/tht-runner.js";
+import type {
+  OllamaEnsureResult,
+  SemanticReadinessCode,
+  ThtRunner,
+} from "../tht/tht-runner.js";
 import type { PrincipalContext } from "../auth/principal.js";
+import type { WorkspaceDescriptor } from "../workspaces/schema.js";
+
+export type ReadinessResult = OllamaEnsureResult & { code?: SemanticReadinessCode };
 
 interface ReadyEntry {
   expiresAt: number;
-  result: OllamaEnsureResult;
+  result: ReadinessResult;
 }
 
 /**
@@ -11,7 +18,7 @@ interface ReadyEntry {
  * Failures are deliberately not cached so a submit can retry after a transient outage.
  */
 export class ReadinessManager {
-  private inFlight = new Map<string, Promise<OllamaEnsureResult>>();
+  private inFlight = new Map<string, Promise<ReadinessResult>>();
   private ready = new Map<string, ReadyEntry>();
 
   constructor(
@@ -21,7 +28,11 @@ export class ReadinessManager {
     private now: () => number = Date.now,
   ) {}
 
-  ensure(workspace = "", principal?: PrincipalContext): Promise<OllamaEnsureResult> {
+  ensure(
+    workspace = "",
+    principal?: PrincipalContext,
+    descriptor?: WorkspaceDescriptor,
+  ): Promise<ReadinessResult> {
     const key = `${principal?.issuer ?? ""}\0${principal?.subject ?? ""}\0${workspace}`;
     const cached = this.ready.get(key);
     if (cached && cached.expiresAt > this.now()) return Promise.resolve(cached.result);
@@ -32,7 +43,20 @@ export class ReadinessManager {
 
     const runner = principal && typeof (this.tht as any).withPrincipal === "function"
       ? this.tht.withPrincipal(principal) : this.tht;
-    const pending = runner.ollamaEnsure(workspace, this.timeoutSec)
+    const pending = (async (): Promise<ReadinessResult> => {
+      try {
+        if (descriptor) {
+          const qdrant = await runner.qdrantEnsure(descriptor, this.timeoutSec);
+          if (!qdrant.ok) return qdrant;
+        }
+        const ollama = await runner.ollamaEnsure(workspace, this.timeoutSec);
+        return ollama.ok
+          ? ollama
+          : { ...ollama, code: "workspace_not_activatable" };
+      } catch {
+        return { ok: false, code: "workspace_not_activatable" };
+      }
+    })()
       .then((result) => {
         if (result.ok) {
           this.ready.set(key, { result, expiresAt: this.now() + this.ttlMs });
diff --git a/backend/src/tht/tht-runner.ts b/backend/src/tht/tht-runner.ts
index fbc64b83..43be047c 100644
--- a/backend/src/tht/tht-runner.ts
+++ b/backend/src/tht/tht-runner.ts
@@ -15,7 +15,11 @@ import {
   type RuntimePaths,
   type SemanticRuntimeConfig,
 } from "../workspaces/runtime-renderer.js";
-import { parseWorkspaceYaml } from "../workspaces/schema.js";
+import {
+  parseWorkspaceYaml,
+  validateOperationalWorkspace,
+  type WorkspaceDescriptor,
+} from "../workspaces/schema.js";
 
 export interface ThtConfig extends SecretBundleConfig {
   thtBin: string;
@@ -25,6 +29,7 @@ export interface ThtConfig extends SecretBundleConfig {
   runtimeSnapshotRoot?: string;
   secretRoots?: readonly string[];
   semanticRuntime: SemanticRuntimeConfig;
+  qdrantRequest?: typeof fetch;
 }
 
 export interface RuntimeConfigLease {
@@ -64,6 +69,24 @@ export interface OllamaEnsureResult {
   model_name?: string;
 }
 
+export type SemanticReadinessCode = "workspace_not_activatable" | "semantic_index_incompatible";
+
+export interface QdrantEnsureResult {
+  ok: boolean;
+  code?: SemanticReadinessCode;
+}
+
+const REQUIRED_QDRANT_PAYLOAD_INDEXES = [
+  "content_hash",
+  "document_id",
+  "kind",
+  "record_key",
+  "record_kind",
+  "vector_generation",
+  "workspace_id",
+  "workspace_revision",
+] as const;
+
 interface RuntimeSnapshot {
   path: string;
   dev: number;
@@ -136,7 +159,7 @@ export class ThtRunner {
       if (before.dev !== after.dev || before.ino !== after.ino || before.size !== after.size) {
         throw new Error("workspace snapshot changed while reading");
       }
-      const workspace = parseWorkspaceYaml(source);
+      const workspace = validateOperationalWorkspace(parseWorkspaceYaml(source));
       if (workspace.workspace.id !== identity.workspaceId) {
         throw new Error("workspace snapshot identity does not match its path");
       }
@@ -537,4 +560,52 @@ export class ThtRunner {
       error: parsed?.error ?? (stderr.trim() || `tht ollama ensure exit ${code}`),
     };
   }
+
+  async qdrantEnsure(
+    workspace: WorkspaceDescriptor,
+    timeoutSec: number,
+  ): Promise<QdrantEnsureResult> {
+    let descriptor;
+    try {
+      descriptor = validateOperationalWorkspace(workspace);
+    } catch {
+      return { ok: false, code: "workspace_not_activatable" };
+    }
+    const collection = descriptor.semantic_index.vector_store;
+    const controller = new AbortController();
+    const timer = setTimeout(() => controller.abort(), Math.max(1, timeoutSec) * 1000);
+    try {
+      const url = new URL(
+        `/collections/${encodeURIComponent(collection.collection)}`,
+        this.cfg.semanticRuntime.internalQdrantUrl,
+      );
+      const request = this.cfg.qdrantRequest ?? fetch;
+      const response = await request(url.toString(), { method: "GET", signal: controller.signal });
+      if (response.status === 404) {
+        return { ok: false, code: "semantic_index_incompatible" };
+      }
+      if (!response.ok) return { ok: false, code: "workspace_not_activatable" };
+      const body = await response.json() as any;
+      const result = body?.result;
+      const vectors = result?.config?.params?.vectors;
+      const payloadSchema = result?.payload_schema;
+      const configurationMatches = vectors
+        && vectors.size === collection.dimensions
+        && typeof vectors.distance === "string"
+        && vectors.distance.toLowerCase() === collection.distance;
+      const indexesMatch = payloadSchema
+        && typeof payloadSchema === "object"
+        && REQUIRED_QDRANT_PAYLOAD_INDEXES.every(
+          (field) => payloadSchema[field]?.data_type === "keyword",
+        );
+      return configurationMatches && indexesMatch
+        ? { ok: true }
+        : { ok: false, code: "semantic_index_incompatible" };
+    } catch {
+      return { ok: false, code: "workspace_not_activatable" };
+    } finally {
+      clearTimeout(timer);
+      controller.abort();
+    }
+  }
 }
diff --git a/backend/src/workspaces/registry.ts b/backend/src/workspaces/registry.ts
index 9f3b3c90..84b45380 100644
--- a/backend/src/workspaces/registry.ts
+++ b/backend/src/workspaces/registry.ts
@@ -13,6 +13,7 @@ import {
   isCanonicalWorkspace,
   parseWorkspaceYaml,
   serializeWorkspaceYaml,
+  validateOperationalWorkspace,
   type CanonicalWorkspace,
   type WorkspaceDescriptor,
 } from "./schema.js";
@@ -216,7 +217,9 @@ export class WorkspaceRegistry {
       }
       let workspace: WorkspaceDescriptor;
       try {
-        workspace = parseWorkspaceYaml(await readFile(revision.snapshotPath, "utf8"));
+        workspace = validateOperationalWorkspace(
+          parseWorkspaceYaml(await readFile(revision.snapshotPath, "utf8")),
+        );
       } catch (error) {
         throw workspaceError(error);
       }
@@ -259,7 +262,10 @@ export class WorkspaceRegistry {
     const snapshotPath = this.snapshotPath(safeCommit(commit), id);
     try {
       const source = await readFile(snapshotPath, "utf8");
-      return { workspace: parseWorkspaceYaml(source), workspaceConfigPath: snapshotPath };
+      return {
+        workspace: validateOperationalWorkspace(parseWorkspaceYaml(source)),
+        workspaceConfigPath: snapshotPath,
+      };
     } catch (error) {
       throw workspaceError(error);
     }
diff --git a/backend/test/readiness-manager.test.ts b/backend/test/readiness-manager.test.ts
index be0cb039..5eb22fcc 100644
--- a/backend/test/readiness-manager.test.ts
+++ b/backend/test/readiness-manager.test.ts
@@ -1,6 +1,21 @@
 import { expect, test } from "vitest";
 import { ReadinessManager } from "../src/runtime/readiness-manager.js";
 
+const workspace = {
+  workspace: { schema_version: 3, id: "psd", name: "PSD", language: "it" },
+  dwh: {
+    engine: "postgres", database: "warehouse", schema: "public",
+    supported_transports: ["postgres_direct"],
+  },
+  semantic_index: {
+    vector_store: { engine: "qdrant", collection: "psd", dimensions: 1024, distance: "cosine" },
+    embedding: {
+      provider: "ollama_internal", model: "qwen3-embedding:0.6b", dimensions: 1024,
+    },
+  },
+  llm_policy: { allowed: ["zai/glm-5.2"] },
+} as const;
+
 function deferred<T>() {
   let resolve!: (value: T) => void;
   const promise = new Promise<T>((r) => { resolve = r; });
@@ -60,3 +75,31 @@ test("readiness does not cache failed results", async () => {
   await expect(readiness.ensure("psd")).resolves.toMatchObject({ ok: true });
   expect(calls).toBe(2);
 });
+
+test("readiness checks Qdrant before Ollama and skips Ollama on semantic incompatibility", async () => {
+  let ollamaCalls = 0;
+  const tht = {
+    qdrantEnsure: async () => ({ ok: false, code: "semantic_index_incompatible" }),
+    ollamaEnsure: async () => { ollamaCalls += 1; return { ok: true }; },
+  } as any;
+  const readiness = new ReadinessManager(tht, 60);
+
+  await expect(readiness.ensure("/registry/psd.yaml", undefined, workspace as any)).resolves.toEqual({
+    ok: false,
+    code: "semantic_index_incompatible",
+  });
+  expect(ollamaCalls).toBe(0);
+});
+
+test("readiness returns a sanitized activation code when a semantic probe throws", async () => {
+  const tht = {
+    qdrantEnsure: async () => { throw new Error("dial http://qdrant:6333/private"); },
+    ollamaEnsure: async () => ({ ok: true }),
+  } as any;
+  const readiness = new ReadinessManager(tht, 60);
+
+  await expect(readiness.ensure("/registry/psd.yaml", undefined, workspace as any)).resolves.toEqual({
+    ok: false,
+    code: "workspace_not_activatable",
+  });
+});
diff --git a/backend/test/routes-sessions.test.ts b/backend/test/routes-sessions.test.ts
index a1461109..451590e4 100644
--- a/backend/test/routes-sessions.test.ts
+++ b/backend/test/routes-sessions.test.ts
@@ -14,17 +14,34 @@ import { validateDeclarativePiConfig } from "../src/pi/managed-config.js";
 const FAKE = path.resolve("../harness/tests/fake_pi/fake_pi_rpc.mjs");
 const SCRIPT = path.resolve("../harness/tests/fake_pi/scripts/f1_disambiguation.json");
 
+function operationalWorkspace(id = "default") {
+  return {
+    workspace: { schema_version: 3, id, name: id, language: "en" },
+    dwh: {
+      engine: "postgres", database: "warehouse", schema: "public",
+      supported_transports: ["postgres_direct"],
+    },
+    semantic_index: {
+      vector_store: {
+        engine: "qdrant", collection: id, dimensions: 1024, distance: "cosine",
+      },
+      embedding: {
+        provider: "ollama_internal", model: "qwen3-embedding:0.6b", dimensions: 1024,
+      },
+    },
+    llm_policy: {
+      allowed: ["zai/glm-5.2", "deepseek/deepseek-v4-pro", "local-qwen/qwen3.6-35b-a3b"],
+    },
+  } as const;
+}
+
 const defaultWorkspaceRegistry = {
   list: vi.fn(async () => [{
     id: "default", commit: "e".repeat(40), blob: "f".repeat(40),
     snapshotPath: `/data/workspace-registry/snapshots/${"e".repeat(40)}/default.yaml`, state: "operational",
   }]),
   read: vi.fn(async (id: string) => ({
-    workspace: {
-      llm_policy: {
-        allowed: ["zai/glm-5.2", "deepseek/deepseek-v4-pro", "local-qwen/qwen3.6-35b-a3b"],
-      },
-    },
+    workspace: operationalWorkspace(id),
     revision: {
       id, commit: "e".repeat(40), blob: "f".repeat(40),
       snapshotPath: `/data/workspace-registry/snapshots/${"e".repeat(40)}/${id}.yaml`, state: "operational",
@@ -33,9 +50,13 @@ const defaultWorkspaceRegistry = {
 };
 
 function buildApp(config: Parameters<typeof buildRealApp>[0], deps: Record<string, unknown> = {}) {
+  const thtRunner = deps.thtRunner
+    ? { qdrantEnsure: async () => ({ ok: true }), ...(deps.thtRunner as object) }
+    : undefined;
   return buildRealApp(config, {
     workspaceRuntimeSupport: () => true,
     ...deps,
+    ...(thtRunner ? { thtRunner } : {}),
     workspaceRegistry: { ...defaultWorkspaceRegistry, ...(deps.workspaceRegistry as object | undefined) },
   } as any);
 }
@@ -663,7 +684,7 @@ test("session lifecycle locates a B session when installation default is A", asy
       ],
       readPinned: vi.fn(async (id: string, revision: string) => {
         expect([id, revision]).toEqual(["b-workspace", "c".repeat(40)]);
-        return { workspace: { llm_policy: { allowed: ["zai/glm-5.2"] } }, workspaceConfigPath: bPinnedPath };
+        return { workspace: operationalWorkspace(id), workspaceConfigPath: bPinnedPath };
       }),
     } as any,
   });
@@ -932,7 +953,7 @@ test("POST /sessions/:id/resume uses the manifest's retained workspace revision"
     getSettings: () => ({ workspace: "legacy" }) as any,
     workspaceRegistry: {
       readPinned: vi.fn(async () => ({
-        workspace: { workspace: { id: "psd-clinical" } },
+        workspace: operationalWorkspace("psd-clinical"),
         revision: {
           id: "psd-clinical", commit: "a".repeat(40), blob: "b".repeat(40),
           snapshotPath: "/data/workspace-registry/snapshots/aaaaaaaa/psd-clinical.yaml", state: "operational",
@@ -968,6 +989,61 @@ test("POST /sessions/:id/resume returns a sanitized error when its retained revi
   expect(response.json()).toMatchObject({ code: "workspace_revision_unavailable" });
 });
 
+test("POST /sessions/:id/resume rejects a pinned schema-v2 workspace before readiness or runtime", async () => {
+  const readiness = vi.fn(async () => ({ ok: true }));
+  const reopenSession = vi.fn(async () => {});
+  const acquireWorkspaceRuntime = vi.fn();
+  const createFor = vi.fn();
+  const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
+    thtRunner: {
+      sessionShow: async () => ({
+        status: "open", archived: false,
+        workspace_id: "psd-clinical", workspace_revision: "a".repeat(40),
+      }),
+      reopenSession,
+      acquireWorkspaceRuntime,
+    } as any,
+    readiness: { ensure: readiness } as any,
+    mgr: { get: () => undefined, createFor } as any,
+    getSettings: () => ({ workspace: "legacy" }) as any,
+    workspaceRegistry: {
+      readPinned: vi.fn(async () => ({
+        workspace: {
+          workspace: { schema_version: 2, id: "psd-clinical", name: "PSD", language: "it" },
+          dwh: {
+            engine: "postgres", database: "warehouse", schema: "public",
+            supported_transports: ["rest_api"],
+          },
+          semantic_index: {
+            vector_store: {
+              engine: "pgvector", database: "warehouse", schema: "vectors",
+              collection: "documents", dimensions: 768, distance: "cosine",
+              supported_transports: ["rest_api"],
+            },
+            embedding: {
+              provider: "ollama_compatible", model: "nomic-embed-text", dimensions: 768,
+            },
+          },
+          llm_policy: { allowed: ["zai/glm-5.2"] },
+        },
+        workspaceConfigPath: `/data/workspace-registry/snapshots/${"a".repeat(40)}/psd-clinical.yaml`,
+      })),
+    } as any,
+  });
+
+  const response = await app.inject({ method: "POST", url: "/sessions/pinned-v2/resume" });
+
+  expect(response.statusCode).toBe(409);
+  expect(response.json()).toEqual({
+    code: "workspace_revision_unavailable",
+    error: "Session workspace configuration is unavailable. Check configuration and try again.",
+  });
+  expect(readiness).not.toHaveBeenCalled();
+  expect(reopenSession).not.toHaveBeenCalled();
+  expect(acquireWorkspaceRuntime).not.toHaveBeenCalled();
+  expect(createFor).not.toHaveBeenCalled();
+});
+
 test("a pruned pin blocks Resume but not active or mutation lifecycle routes", async () => {
   const activePath = "/registry/snapshots/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/b-workspace.yaml";
   const prunedError = "cannot read /registry/snapshots/secret-pruned-revision/b-workspace.yaml";
@@ -2340,11 +2416,35 @@ test("POST /sessions readiness failure returns one fixed public message without
   expect(res.statusCode).toBe(503);
   expect(res.json()).toEqual({
     error: "Session services are not ready. Check configuration and connectivity, then try again.",
+    code: "workspace_not_activatable",
   });
   expect(res.body).not.toMatch(/secret\.invalid|DO_NOT_LEAK|\/srv\/private\/model-key/);
   expect(createdCalled).toBe(false);
 });
 
+test.each(["semantic_index_incompatible", "workspace_not_activatable"] as const)(
+  "POST /sessions does not persist when Qdrant readiness returns %s",
+  async (code) => {
+    const sessionNew = vi.fn(async () => ({ id: "must-not-exist" }));
+    const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
+      thtRunner: { sessionNew } as any,
+      readiness: { ensure: async () => ({ ok: false, code }) } as any,
+      getSettings: () => ({ workspace: "psd" }) as any,
+    });
+
+    const response = await app.inject({
+      method: "POST", url: "/sessions", payload: { question: "q" },
+    });
+
+    expect(response.statusCode).toBe(503);
+    expect(response.json()).toEqual({
+      error: "Session services are not ready. Check configuration and connectivity, then try again.",
+      code,
+    });
+    expect(sessionNew).not.toHaveBeenCalled();
+  },
+);
+
 test("POST /sessions returns storage 503 before creating a Pi runtime when session persistence fails", async () => {
   let piCreated = false;
   const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
@@ -2365,8 +2465,10 @@ test("POST /sessions returns storage 503 before creating a Pi runtime when sessi
 
 test("POST /sessions proceeds when ollamaEnsure succeeds", async () => {
   let ensureWs: string | undefined;
+  const qdrantEnsure = vi.fn(async () => ({ ok: true }));
   const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
     thtRunner: {
+      qdrantEnsure,
       ollamaEnsure: async (ws: string) => { ensureWs = ws; return { ok: true }; },
       searchPack: async () => {},
       sessionNew: async () => ({ id: "s1" }),
@@ -2376,6 +2478,7 @@ test("POST /sessions proceeds when ollamaEnsure succeeds", async () => {
   });
   const res = await app.inject({ method: "POST", url: "/sessions", payload: { question: "q" } });
   expect(res.json()).toEqual({ id: "s1" });
+  expect(qdrantEnsure).toHaveBeenCalledWith(operationalWorkspace("psd"), 60);
   expect(ensureWs).toContain(`/snapshots/${"e".repeat(40)}/psd.yaml`);
 });
 
@@ -2574,6 +2677,7 @@ test("POST /sessions/:id/resume readiness failure returns the same fixed public
   expect(res.statusCode).toBe(503);
   expect(res.json()).toEqual({
     error: "Session services are not ready. Check configuration and connectivity, then try again.",
+    code: "workspace_not_activatable",
   });
   expect(res.body).not.toMatch(/secret\.invalid|DO_NOT_LEAK|\/srv\/private\/resume-key/);
 });
diff --git a/backend/test/routes-workspaces.test.ts b/backend/test/routes-workspaces.test.ts
index d422be5b..481a86fa 100644
--- a/backend/test/routes-workspaces.test.ts
+++ b/backend/test/routes-workspaces.test.ts
@@ -238,7 +238,7 @@ test("validates a canonical workspace and runs the injected installation diagnos
   expect(diagnose).not.toHaveBeenCalled();
 });
 
-test("runs the injected installation diagnostic for a migration-required v2 workspace when legacy bindings resolve", async () => {
+test("rejects a migration-required v2 workspace before resolving semantic diagnostics", async () => {
   const diagnose = vi.fn(async () => ({
     activatable: false,
     diagnostics: [{ level: "error" as const, code: "binding_missing" as const, field: "THT_WS_PSD_CLINICAL_VECTOR_BASE_URL", message: "Installation binding is missing or invalid." }],
@@ -257,13 +257,12 @@ test("runs the injected installation diagnostic for a migration-required v2 work
   try {
     const testResult = await app.inject({ method: "POST", url: "/workspaces/psd-clinical/test", payload: {} });
 
-    expect(testResult.statusCode).toBe(200);
-    expect(testResult.json()).toMatchObject({ activatable: false, diagnostics: [{ code: "binding_missing" }] });
-    expect(diagnose).toHaveBeenCalledWith(workspaceV2, expect.objectContaining({
-      dwh: expect.objectContaining({ transport: "rest_api", missing: [] }),
-      vector: expect.objectContaining({ transport: "rest_api", missing: [] }),
-      embedding: expect.objectContaining({ transport: "rest_api", missing: [] }),
-    }), { writeProbe: false });
+    expect(testResult.statusCode).toBe(400);
+    expect(testResult.json()).toEqual({
+      code: "workspace_not_activatable",
+      message: "Workspace cannot be activated on this installation.",
+    });
+    expect(diagnose).not.toHaveBeenCalled();
   } finally {
     process.env = originalEnv;
   }
diff --git a/backend/test/tht-qdrant-readiness.test.ts b/backend/test/tht-qdrant-readiness.test.ts
new file mode 100644
index 00000000..6eaa0a83
--- /dev/null
+++ b/backend/test/tht-qdrant-readiness.test.ts
@@ -0,0 +1,100 @@
+import { expect, test, vi } from "vitest";
+import { ThtRunner } from "../src/tht/tht-runner.js";
+import type { CanonicalWorkspace } from "../src/workspaces/schema.js";
+
+const keywordIndexes = [
+  "content_hash", "document_id", "kind", "record_key", "record_kind",
+  "vector_generation", "workspace_id", "workspace_revision",
+];
+
+const workspace: CanonicalWorkspace = {
+  workspace: { schema_version: 3, id: "psd", name: "PSD", language: "it" },
+  dwh: {
+    engine: "postgres", database: "warehouse", schema: "public",
+    supported_transports: ["postgres_direct"],
+  },
+  semantic_index: {
+    vector_store: { engine: "qdrant", collection: "psd", dimensions: 1024, distance: "cosine" },
+    embedding: {
+      provider: "ollama_internal", model: "qwen3-embedding:0.6b", dimensions: 1024,
+    },
+  },
+  llm_policy: { allowed: ["zai/glm-5.2"] },
+};
+
+function runner(request: (...args: any[]) => Promise<any>) {
+  return new ThtRunner({
+    thtBin: "tht",
+    harnessDir: "/harness",
+    configPath: "config/tht.yaml",
+    semanticRuntime: {
+      internalQdrantUrl: "http://qdrant:6333",
+      internalEmbeddingUrl: "http://embedding:11434",
+      internalEmbeddingModel: "qwen3-embedding:0.6b",
+      internalEmbeddingDimensions: 1024,
+    },
+    qdrantRequest: request,
+  });
+}
+
+function response(status: number, body: unknown) {
+  return {
+    ok: status >= 200 && status < 300,
+    status,
+    json: async () => body,
+  };
+}
+
+function collection(overrides: Record<string, unknown> = {}) {
+  return {
+    result: {
+      config: { params: { vectors: { size: 1024, distance: "Cosine" } } },
+      payload_schema: Object.fromEntries(keywordIndexes.map((field) => [field, { data_type: "keyword" }])),
+      ...overrides,
+    },
+  };
+}
+
+test("Qdrant readiness uses only the internal URL and accepts the exact collection contract", async () => {
+  const request = vi.fn(async () => response(200, collection()));
+
+  await expect(runner(request).qdrantEnsure(workspace, 3)).resolves.toEqual({ ok: true });
+  expect(request).toHaveBeenCalledOnce();
+  expect(request.mock.calls[0][0]).toBe("http://qdrant:6333/collections/psd");
+  expect(request.mock.calls[0][1]).toMatchObject({ method: "GET", signal: expect.any(AbortSignal) });
+});
+
+test("Qdrant readiness classifies a missing collection as semantic incompatibility", async () => {
+  const request = vi.fn(async () => response(404, { status: "error", detail: "secret" }));
+
+  await expect(runner(request).qdrantEnsure(workspace, 3)).resolves.toEqual({
+    ok: false,
+    code: "semantic_index_incompatible",
+  });
+});
+
+test.each([
+  ["dimensions", collection({
+    config: { params: { vectors: { size: 768, distance: "Cosine" } } },
+  })],
+  ["distance", collection({
+    config: { params: { vectors: { size: 1024, distance: "Dot" } } },
+  })],
+  ["payload indexes", collection({ payload_schema: { workspace_id: { data_type: "keyword" } } })],
+])("Qdrant readiness rejects incompatible %s", async (_label, body) => {
+  const request = vi.fn(async () => response(200, body));
+
+  await expect(runner(request).qdrantEnsure(workspace, 3)).resolves.toEqual({
+    ok: false,
+    code: "semantic_index_incompatible",
+  });
+});
+
+test("Qdrant readiness sanitizes unreachable internal service failures", async () => {
+  const request = vi.fn(async () => { throw new Error("connect http://qdrant:6333/private"); });
+
+  await expect(runner(request).qdrantEnsure(workspace, 3)).resolves.toEqual({
+    ok: false,
+    code: "workspace_not_activatable",
+  });
+});
diff --git a/backend/test/workspace-registry.test.ts b/backend/test/workspace-registry.test.ts
index 5835bbce..0111b9bd 100644
--- a/backend/test/workspace-registry.test.ts
+++ b/backend/test/workspace-registry.test.ts
@@ -662,6 +662,9 @@ test("lists a schema v2 descriptor as migration_required and refuses to acquire
   await expect(registry.acquireSessionRevision("psd-clinical")).rejects.toMatchObject({
     code: "workspace_invalid",
   });
+  await expect(registry.readPinned("psd-clinical", remote.initialCommit)).rejects.toMatchObject({
+    code: "workspace_invalid",
+  });
 });
 
 test("lists operational descriptors retained after their workspace was removed from the active revision", async () => {
diff --git a/backend/test/workspace-runtime-handoff.test.ts b/backend/test/workspace-runtime-handoff.test.ts
index 63c7eebe..73b1febe 100644
--- a/backend/test/workspace-runtime-handoff.test.ts
+++ b/backend/test/workspace-runtime-handoff.test.ts
@@ -42,6 +42,18 @@ llm_policy:
   allowed: [zai/glm-5.2]
 `;
 
+const migrationRequiredWorkspace = canonicalWorkspace
+  .replace("schema_version: 3", "schema_version: 2")
+  .replace(
+    "    engine: qdrant\n    collection: psd-clinical",
+    "    engine: pgvector\n    database: analytics\n    schema: vectors\n    collection: documents",
+  )
+  .replace("    dimensions: 1024", "    dimensions: 768")
+  .replace("    distance: cosine", "    distance: cosine\n    supported_transports: [rest_api]")
+  .replace("    provider: ollama_internal", "    provider: ollama_compatible")
+  .replace("    model: qwen3-embedding:0.6b", "    model: nomic-embed-text")
+  .replace("    dimensions: 1024", "    dimensions: 768");
+
 afterEach(() => {
   vi.unstubAllEnvs();
   roots.splice(0).forEach((root) => rmSync(root, { recursive: true, force: true }));
@@ -51,7 +63,7 @@ async function git(cwd: string, args: string[]): Promise<string> {
   return (await runFile("git", args, { cwd })).stdout.trim();
 }
 
-async function fixture() {
+async function fixture(workspaceSource = canonicalWorkspace) {
   const root = mkdtempSync(join(tmpdir(), "tht-runtime-handoff-"));
   roots.push(root);
   const remote = join(root, "remote.git");
@@ -65,7 +77,7 @@ async function fixture() {
   await git(source, ["config", "user.name", "Runtime Handoff Test"]);
   await git(source, ["config", "user.email", "runtime-handoff@example.invalid"]);
   mkdirSync(join(source, "workspaces"));
-  writeFileSync(join(source, "workspaces", "psd-clinical.yaml"), canonicalWorkspace);
+  writeFileSync(join(source, "workspaces", "psd-clinical.yaml"), workspaceSource);
   await git(source, ["add", "workspaces/psd-clinical.yaml"]);
   await git(source, ["commit", "-m", "Canonical workspace"]);
   await git(source, ["remote", "add", "origin", remote]);
@@ -160,6 +172,15 @@ test("separate runtime leases hand off one stable logical workspace identity", a
   }
 });
 
+test("ThtRunner refuses to render a migration-required registry snapshot", async () => {
+  const f = await fixture(migrationRequiredWorkspace);
+  const runner = runnerFor(f);
+
+  expect(() => runner.acquireWorkspaceRuntime(f.revision.snapshotPath)).toThrow(
+    "Workspace descriptor requires explicit migration to schema version 3",
+  );
+});
+
 test("local GET sessions mine uses the real canonical handoff and returns an empty inventory", async () => {
   const f = await fixture();
   const app = buildApp(loadConfig({
diff --git a/harness/tests/test_qdrant_vector_store.py b/harness/tests/test_qdrant_vector_store.py
index 5da91c5b..a729f611 100644
--- a/harness/tests/test_qdrant_vector_store.py
+++ b/harness/tests/test_qdrant_vector_store.py
@@ -212,6 +212,27 @@ def test_upsert_refuses_collection_dimension_or_distance_mismatch_without_recrea
     assert creates == []
 
 
+def test_health_fails_when_the_bound_collection_is_missing():
+    fake = FakeQdrantHttp()
+
+    health = _store(fake).health()
+
+    assert health.ok is False
+    assert health.read_reachable is False
+    assert health.write_reachable is False
+    assert "missing" in (health.detail or "").lower()
+
+
+def test_health_fails_when_required_payload_indexes_are_missing_without_creating_them():
+    fake = FakeQdrantHttp()
+    fake.collection = {"vectors": {"size": 1024, "distance": "Cosine"}}
+
+    health = _store(fake).health()
+
+    assert health.ok is False
+    assert fake.payload_indexes == set()
+
+
 @pytest.mark.parametrize(
     ("record", "semantic_kind"),
     [
@@ -307,6 +328,90 @@ def test_existing_hashes_health_and_exact_generation_inventory_and_delete():
     assert health.dimension_compatible is True
 
 
+def test_metadata_search_rejects_a_workspace_id_different_from_the_bound_adapter():
+    fake = FakeQdrantHttp()
+    store = _store(fake)
+    generation = "gen:" + "1" * 32
+    store.upsert("evidence", [
+        _write_record(
+            f"demo:{generation}:chunk:1",
+            "evidence",
+            metadata={
+                "workspace_id": "demo", "vector_generation": generation,
+                "document_id": "doc:shared",
+            },
+        ),
+    ])
+    foreign = next(iter(fake.points.values())).copy()
+    foreign["id"] = point_id("other", "evidence", f"other:{generation}:chunk:1")
+    foreign["payload"] = {
+        **foreign["payload"],
+        "workspace_id": "other",
+        "record_key": f"other:{generation}:chunk:1",
+        "ref": "ref:foreign",
+        "title": "foreign",
+        "content": "foreign",
+    }
+    fake.points[foreign["id"]] = foreign
+
+    with pytest.raises(VectorStoreError, match="workspace namespace does not match"):
+        store.search(
+            ["evidence"], [0.2] * 1024, limit=5, kinds=["evidence"],
+            metadata_filter={
+                "workspace_id": "other",
+                "vector_generation": generation,
+                "document_ids": ["doc:shared"],
+            },
+        )
+
+
+def test_generation_inventory_rejects_a_workspace_id_different_from_the_bound_adapter():
+    fake = FakeQdrantHttp()
+    store = _store(fake)
+
+    with pytest.raises(VectorStoreError, match="workspace namespace does not match"):
+        store.list_evidence_generations("evidence", "other")
+    assert not any(call[1].endswith("/points/scroll") for call in fake.calls)
+
+
+def test_generation_delete_cannot_mutate_foreign_workspace_or_non_evidence_points():
+    fake = FakeQdrantHttp()
+    store = _store(fake)
+    generation = "gen:" + "1" * 32
+    store.upsert("evidence", [
+        _write_record(
+            f"demo:{generation}:chunk:1",
+            "evidence",
+            metadata={
+                "workspace_id": "demo", "vector_generation": generation,
+                "document_id": "doc:demo",
+            },
+        ),
+    ])
+    demo = next(iter(fake.points.values()))
+    foreign = demo.copy()
+    foreign["id"] = point_id("other", "evidence", f"other:{generation}:chunk:1")
+    foreign["payload"] = {
+        **demo["payload"], "workspace_id": "other",
+        "record_key": f"other:{generation}:chunk:1",
+    }
+    fake.points[foreign["id"]] = foreign
+    memory = demo.copy()
+    memory["id"] = point_id("other", "memory", "memory:foreign")
+    memory["payload"] = {
+        **demo["payload"], "workspace_id": "other", "kind": "memory",
+        "record_kind": "memory", "record_key": "memory:foreign",
+    }
+    fake.points[memory["id"]] = memory
+    before = set(fake.points)
+
+    with pytest.raises(VectorStoreError, match="workspace namespace does not match"):
+        store.delete_generation("evidence", generation, "other")
+
+    assert set(fake.points) == before
+    assert not any(call[1].endswith("/points/delete?wait=true") for call in fake.calls)
+
+
 def test_delete_kinds_is_workspace_scoped_and_preserves_other_semantic_kinds():
     fake = FakeQdrantHttp()
     store = _store(fake)
diff --git a/harness/tht/adapters/vector/qdrant.py b/harness/tht/adapters/vector/qdrant.py
index 7d880d82..d3073f15 100644
--- a/harness/tht/adapters/vector/qdrant.py
+++ b/harness/tht/adapters/vector/qdrant.py
@@ -94,14 +94,11 @@ class QdrantVectorStore:
                 expected_dimension=self._expected_dimension,
             )
 
-        dimensions = ()
-        compatible = None
-        if info is not None:
-            dimension = info["config"]["params"]["vectors"]["size"]
-            dimensions = (dimension,)
-            compatible = (
-                None if self._expected_dimension is None else dimensions == (self._expected_dimension,)
-            )
+        dimension = info["config"]["params"]["vectors"]["size"]
+        dimensions = (dimension,)
+        compatible = (
+            None if self._expected_dimension is None else dimensions == (self._expected_dimension,)
+        )
         return VectorHealth(
             ok=compatible is not False,
             read_configured=True,
@@ -142,12 +139,11 @@ class QdrantVectorStore:
                 or not isinstance(workspace_id, str)
             ):
                 raise VectorStoreError("Invalid vector metadata filter")
-            filter_must = [
-                {"key": "workspace_id", "match": {"value": workspace_id}},
-                {"key": "record_kind", "match": {"any": allowed_record_kinds}},
+            self._require_bound_workspace(workspace_id)
+            filter_must.extend([
                 {"key": "vector_generation", "match": {"value": generation}},
                 {"key": "document_id", "match": {"any": document_ids}},
-            ]
+            ])
         response = self._call(
             "POST",
             f"/collections/{self._collection}/points/query",
@@ -232,27 +228,19 @@ class QdrantVectorStore:
             raise VectorStoreError("Only exact Evidence generations may be deleted")
         if _WORKSPACE.fullmatch(workspace_id) is None:
             raise VectorStoreError("Invalid Evidence workspace namespace")
+        self._require_bound_workspace(workspace_id)
+        must = [
+            *self._workspace_filter(),
+            {"key": "record_kind", "match": {"any": ["evidence"]}},
+            {"key": "vector_generation", "match": {"value": generation}},
+        ]
         before = len(
-            self._scroll(
-                [
-                    {"key": "workspace_id", "match": {"value": workspace_id}},
-                    {"key": "record_kind", "match": {"any": ["evidence"]}},
-                    {"key": "vector_generation", "match": {"value": generation}},
-                ]
-            )
+            self._scroll(must)
         )
         self._call(
             "POST",
             f"/collections/{self._collection}/points/delete?wait=true",
-            {
-                "filter": {
-                    "must": [
-                        {"key": "workspace_id", "match": {"value": workspace_id}},
-                        {"key": "record_kind", "match": {"any": ["evidence"]}},
-                        {"key": "vector_generation", "match": {"value": generation}},
-                    ]
-                }
-            },
+            {"filter": {"must": must}},
         )
         return before
 
@@ -261,9 +249,10 @@ class QdrantVectorStore:
             raise VectorStoreError("Only exact Evidence generations may be listed")
         if _WORKSPACE.fullmatch(workspace_id) is None:
             raise VectorStoreError("Invalid Evidence workspace namespace")
+        self._require_bound_workspace(workspace_id)
         points = self._scroll(
             [
-                {"key": "workspace_id", "match": {"value": workspace_id}},
+                *self._workspace_filter(),
                 {"key": "record_kind", "match": {"any": ["evidence"]}},
             ]
         )
@@ -279,6 +268,10 @@ class QdrantVectorStore:
     def _workspace_filter(self) -> list[dict]:
         return [{"key": "workspace_id", "match": {"value": self._workspace_id}}]
 
+    def _require_bound_workspace(self, workspace_id: str) -> None:
+        if workspace_id != self._workspace_id:
+            raise VectorStoreError("Evidence workspace namespace does not match bound workspace")
+
     def _allowed_record_kinds(
         self, collections: list[str], kinds: list[str] | None
     ) -> list[str]:
@@ -303,7 +296,7 @@ class QdrantVectorStore:
         response = self._call("GET", f"/collections/{self._collection}", None, allow_missing=True)
         if response is None:
             if not strict:
-                return None
+                raise VectorStoreError("Qdrant collection is missing")
             self._call(
                 "PUT",
                 f"/collections/{self._collection}",
@@ -329,6 +322,8 @@ class QdrantVectorStore:
             raise VectorStoreError("Qdrant collection configuration mismatch")
         for field_name in _KEYWORD_INDEXES:
             if field_name not in result.get("payload_schema", {}):
+                if not strict:
+                    raise VectorStoreError("Qdrant collection payload indexes mismatch")
                 self._call(
                     "PUT",
                     f"/collections/{self._collection}/index",
diff --git a/scripts/lib/vector-operation-lock.sh b/scripts/lib/vector-operation-lock.sh
new file mode 100644
index 00000000..a148b237
--- /dev/null
+++ b/scripts/lib/vector-operation-lock.sh
@@ -0,0 +1,48 @@
+#!/bin/sh
+
+# Shared, daemon-scoped lock for operations that stop or replace one Compose Qdrant volume.
+# The stopped container name is the atomic primitive; ownership labels prevent a cleanup trap
+# from deleting a lock that it did not create.
+vector_operation_lock_init() {
+  operation_lock_name="${expected_volume_name}-operation-lock"
+  operation_lock_owner="${project_name}-$$-$(date -u +%Y%m%dT%H%M%S)"
+  operation_lock_acquired=0
+}
+
+acquire_vector_operation_lock() {
+  if docker create \
+    --name "$operation_lock_name" \
+    --label "com.thothii.qdrant-operation-owner=$operation_lock_owner" \
+    --label "com.thothii.qdrant-operation-project=$project_name" \
+    --label "com.thothii.qdrant-operation-volume=$expected_volume_name" \
+    "$helper_image" /bin/true >/dev/null 2>&1; then
+    operation_lock_acquired=1
+    return 0
+  fi
+
+  if docker inspect "$operation_lock_name" >/dev/null 2>&1; then
+    echo "Qdrant operation already in progress for $expected_volume_name" >&2
+  else
+    echo "Unable to acquire Qdrant operation lock for $expected_volume_name" >&2
+  fi
+  return 2
+}
+
+release_vector_operation_lock() {
+  [ "${operation_lock_acquired:-0}" -eq 1 ] || return 0
+  metadata=$(docker inspect --format \
+    '{{ index .Config.Labels "com.thothii.qdrant-operation-owner" }} {{ index .Config.Labels "com.thothii.qdrant-operation-volume" }}' \
+    "$operation_lock_name" 2>/dev/null || true)
+  set -- $metadata
+  if [ "${1-}" != "$operation_lock_owner" ] || [ "${2-}" != "$expected_volume_name" ]; then
+    echo "Qdrant operation lock ownership changed; refusing to remove it" >&2
+    operation_lock_acquired=0
+    return 1
+  fi
+  if ! docker rm -f "$operation_lock_name" >/dev/null; then
+    echo "Unable to release Qdrant operation lock for $expected_volume_name" >&2
+    operation_lock_acquired=0
+    return 1
+  fi
+  operation_lock_acquired=0
+}
diff --git a/scripts/test-vector-backup-restore-safety.sh b/scripts/test-vector-backup-restore-safety.sh
index 7c0d947b..d173d224 100755
--- a/scripts/test-vector-backup-restore-safety.sh
+++ b/scripts/test-vector-backup-restore-safety.sh
@@ -3,7 +3,17 @@ set -eu
 
 cd "$(dirname "$0")/.."
 tmp=$(mktemp -d)
-trap 'rm -rf "$tmp"' EXIT HUP INT TERM
+holder_pid=
+holder_release="$tmp/holder-release"
+cleanup() {
+  touch "$holder_release"
+  if [ -n "${holder_pid:-}" ]; then
+    kill "$holder_pid" 2>/dev/null || true
+    wait "$holder_pid" 2>/dev/null || true
+  fi
+  rm -rf "$tmp"
+}
+trap cleanup EXIT HUP INT TERM
 fakebin="$tmp/bin"
 mkdir "$fakebin"
 
@@ -28,6 +38,15 @@ run_backup() {
   volume_name=$1
   backup_dir=$2
   output_name=$3
+  if [ -n "${RUN_BLOCK_READY:-}" ]; then
+    : >"$RUN_BLOCK_READY"
+    attempts=0
+    while [ ! -e "${RUN_BLOCK_RELEASE:?}" ]; do
+      attempts=$((attempts + 1))
+      [ "$attempts" -lt 400 ] || exit 24
+      sleep 0.05
+    done
+  fi
   staging=$(mktemp -d "${TMPDIR:-/tmp}/fake-qdrant-backup.XXXXXX")
   mkdir -p "$staging/payload"
   cat >"$staging/manifest.env" <<EOF
@@ -36,12 +55,59 @@ project_name=${PROJECT_NAME:?}
 volume_name=$volume_name
 volume_role=qdrant-data
 helper_image=${HELPER_IMAGE:?}
+created_utc=2026-08-08T17:35:36Z
 EOF
   cp -R "$(volume_dir_for "$volume_name")"/. "$staging/payload"/
   tar -C "$staging" -cf "$backup_dir/$output_name" manifest.env payload
   rm -rf "$staging"
 }
 
+lock_state_root=${LOCK_ROOT:-$(dirname "${VOLUME_ROOT:?}")/locks}
+mkdir -p "$lock_state_root"
+
+if [ "$1" = create ]; then
+  shift
+  lock_name=
+  lock_owner=
+  lock_volume=
+  while [ "$#" -gt 0 ]; do
+    case "$1" in
+      --name) lock_name=$2; shift 2 ;;
+      --label)
+        case "$2" in
+          com.thothii.qdrant-operation-owner=*) lock_owner=${2#*=} ;;
+          com.thothii.qdrant-operation-volume=*) lock_volume=${2#*=} ;;
+        esac
+        shift 2
+        ;;
+      *) shift ;;
+    esac
+  done
+  [ -n "$lock_name" ] && [ -n "$lock_owner" ] && [ -n "$lock_volume" ] || exit 25
+  state="$lock_state_root/$lock_name"
+  mkdir "$state" 2>/dev/null || exit 1
+  printf '%s\n' "$lock_owner" >"$state/owner"
+  printf '%s\n' "$lock_volume" >"$state/volume"
+  printf '%s\n' "$lock_name"
+  exit 0
+fi
+
+if [ "$1" = inspect ]; then
+  for lock_name in "$@"; do :; done
+  state="$lock_state_root/$lock_name"
+  [ -d "$state" ] || exit 1
+  printf '%s %s\n' "$(cat "$state/owner")" "$(cat "$state/volume")"
+  exit 0
+fi
+
+if [ "$1" = rm ]; then
+  for lock_name in "$@"; do :; done
+  state="$lock_state_root/$lock_name"
+  [ -d "$state" ] || exit 1
+  rm -rf "$state"
+  exit 0
+fi
+
 run_restore() {
   volume_name=$1
   backup_dir=$2
@@ -219,6 +285,7 @@ PY
 
 backup_output="$tmp/qdrant-backup.tar"
 docker_log="$tmp/docker-backup.log"
+lock_name="${project}_qdrant-data-operation-lock"
 PATH="$fakebin:$PATH" DOCKER_LOG="$docker_log" PROJECT_NAME="$project" VOLUME_ROOT="$volume_root" \
 HELPER_IMAGE="qdrant/qdrant:v1.18.2@sha256:75eab8c4ba42096724fdcfde8b4de0b5713d529dde32f285a1f86fdcb2c9e50c" \
   ./scripts/vector-backup.sh --project-name "$project" --output "$backup_output" >/dev/null
@@ -231,6 +298,15 @@ tar -xOf "$backup_output" manifest.env | grep -qx "volume_name=$volume_name"
 grep -q "run --rm --mount type=volume,src=$volume_name,dst=/qdrant-data,readonly --mount type=bind,src=$tmp,dst=/backup" "$docker_log"
 grep -q "compose --project-name $project stop qdrant" "$docker_log"
 grep -q "compose --project-name $project start qdrant" "$docker_log"
+grep -q "create --name $lock_name" "$docker_log"
+grep -q "rm -f $lock_name" "$docker_log"
+test ! -e "$tmp/locks/$lock_name"
+lock_line=$(grep -n "create --name $lock_name" "$docker_log" | sed -n '1s/:.*//p')
+volume_line=$(grep -n '^volume ls ' "$docker_log" | sed -n '1s/:.*//p')
+[ "$lock_line" -lt "$volume_line" ] || {
+  echo "backup resolved volume state before acquiring the operation lock" >&2
+  exit 1
+}
 if grep -q "volume inspect --format {{ .Mountpoint }}" "$docker_log"; then
   echo "backup consulted Docker mountpoints" >&2
   exit 1
@@ -240,6 +316,61 @@ if grep -q "prune" "$docker_log"; then
   exit 1
 fi
 
+mkdir -p "$tmp/locks/$lock_name"
+printf '%s\n' foreign-owner >"$tmp/locks/$lock_name/owner"
+printf '%s\n' "$volume_name" >"$tmp/locks/$lock_name/volume"
+foreign_lock_log="$tmp/foreign-lock.log"
+if PATH="$fakebin:$PATH" DOCKER_LOG="$foreign_lock_log" PROJECT_NAME="$project" VOLUME_ROOT="$volume_root" \
+HELPER_IMAGE="qdrant/qdrant:v1.18.2@sha256:75eab8c4ba42096724fdcfde8b4de0b5713d529dde32f285a1f86fdcb2c9e50c" \
+  ./scripts/vector-backup.sh --project-name "$project" --output "$tmp/foreign-lock.tar" \
+  >"$tmp/foreign-lock.out" 2>"$tmp/foreign-lock.err"; then
+  echo "backup ignored a foreign operation lock" >&2
+  exit 1
+fi
+grep -q 'operation already in progress' "$tmp/foreign-lock.err"
+test "$(cat "$tmp/locks/$lock_name/owner")" = foreign-owner
+rm -rf "$tmp/locks/$lock_name"
+
+holder_ready="$tmp/holder-ready"
+holder_output="$tmp/holder.tar"
+holder_log="$tmp/holder.log"
+PATH="$fakebin:$PATH" DOCKER_LOG="$holder_log" PROJECT_NAME="$project" VOLUME_ROOT="$volume_root" \
+RUN_BLOCK_READY="$holder_ready" RUN_BLOCK_RELEASE="$holder_release" \
+HELPER_IMAGE="qdrant/qdrant:v1.18.2@sha256:75eab8c4ba42096724fdcfde8b4de0b5713d529dde32f285a1f86fdcb2c9e50c" \
+  ./scripts/vector-backup.sh --project-name "$project" --output "$holder_output" >/dev/null 2>"$tmp/holder.err" &
+holder_pid=$!
+attempts=0
+while [ ! -e "$holder_ready" ]; do
+  attempts=$((attempts + 1))
+  [ "$attempts" -lt 400 ] || { echo "lock holder did not reach copy phase" >&2; exit 1; }
+  sleep 0.05
+done
+
+for contender in backup restore; do
+  contender_log="$tmp/contender-$contender.log"
+  if [ "$contender" = backup ]; then
+    set -- ./scripts/vector-backup.sh --project-name "$project" --output "$tmp/contender.tar"
+  else
+    set -- ./scripts/vector-restore.sh --project-name "$project" --input "$backup_output" --confirm-project "$project"
+  fi
+  if PATH="$fakebin:$PATH" DOCKER_LOG="$contender_log" PROJECT_NAME="$project" VOLUME_ROOT="$volume_root" \
+  HELPER_IMAGE="qdrant/qdrant:v1.18.2@sha256:75eab8c4ba42096724fdcfde8b4de0b5713d529dde32f285a1f86fdcb2c9e50c" \
+    "$@" >"$tmp/contender-$contender.out" 2>"$tmp/contender-$contender.err"; then
+    echo "$contender interleaved with an active qdrant operation" >&2
+    exit 1
+  fi
+  grep -q 'operation already in progress' "$tmp/contender-$contender.err"
+  if grep -Eq '^volume (ls|inspect)|^compose .* (stop|start) qdrant|^run ' "$contender_log"; then
+    echo "$contender touched qdrant state after lock contention" >&2
+    exit 1
+  fi
+done
+touch "$holder_release"
+wait "$holder_pid"
+holder_pid=
+test -s "$holder_output"
+test ! -e "$tmp/locks/$lock_name"
+
 existing="$tmp/existing.tar"
 printf '%s' sentinel >"$existing"
 if PATH="$fakebin:$PATH" DOCKER_LOG="$tmp/existing.log" PROJECT_NAME="$project" VOLUME_ROOT="$volume_root" \
@@ -392,5 +523,6 @@ fi
 test "$(cat "$volume_dir/collections/demo/state.json")" = rollback-source
 grep -q "compose --project-name $project stop qdrant" "$rollback_log"
 grep -q "compose --project-name $project start qdrant" "$rollback_log"
+test ! -e "$tmp/locks/$lock_name"
 
 echo "qdrant backup/restore archive validation, scoped helper execution, and rollback safety passed."
diff --git a/scripts/vector-backup.sh b/scripts/vector-backup.sh
index 47c3f52c..3efcd18d 100755
--- a/scripts/vector-backup.sh
+++ b/scripts/vector-backup.sh
@@ -28,6 +28,9 @@ output_name=$(basename "$output")
 [ -d "$output_dir" ] || { echo "backup destination directory does not exist" >&2; exit 2; }
 
 expected_volume_name="${project_name}_${volume_role}"
+script_dir=$(CDPATH= cd "$(dirname "$0")" && pwd)
+. "$script_dir/lib/vector-operation-lock.sh"
+vector_operation_lock_init
 
 resolve_volume() {
   names=$(docker volume ls \
@@ -55,24 +58,32 @@ validate_volume_metadata() {
   [ "${3-}" = "$volume_role" ] || { echo "volume metadata role label mismatch" >&2; exit 2; }
 }
 
-volume_name=$(resolve_volume)
-validate_volume_metadata "$volume_name"
-
-running_container=$(docker compose --project-name "$project_name" ps --status running -q qdrant)
 restart_qdrant=0
 temporary_output=
 cleanup() {
   status=$?
+  trap - EXIT HUP INT TERM
   if [ -n "${temporary_output:-}" ] && [ -e "${temporary_output:-}" ]; then
     rm -f "$temporary_output"
   fi
   if [ "$restart_qdrant" -eq 1 ]; then
-    docker compose --project-name "$project_name" start qdrant >/dev/null
+    if ! docker compose --project-name "$project_name" start qdrant >/dev/null; then
+      echo "Unable to restart Qdrant after backup" >&2
+      [ "$status" -ne 0 ] || status=1
+    fi
+  fi
+  if ! release_vector_operation_lock; then
+    [ "$status" -ne 0 ] || status=1
   fi
   exit "$status"
 }
 trap cleanup EXIT HUP INT TERM
 
+acquire_vector_operation_lock
+volume_name=$(resolve_volume)
+validate_volume_metadata "$volume_name"
+running_container=$(docker compose --project-name "$project_name" ps --status running -q qdrant)
+
 if [ -n "$running_container" ]; then
   docker compose --project-name "$project_name" stop qdrant >/dev/null
   restart_qdrant=1
diff --git a/scripts/vector-restore.sh b/scripts/vector-restore.sh
index 6aae4f6a..5ee3a27b 100755
--- a/scripts/vector-restore.sh
+++ b/scripts/vector-restore.sh
@@ -30,15 +30,26 @@ done
 [ -r "$input" ] || { echo "backup input is not readable" >&2; exit 2; }
 
 expected_volume_name="${project_name}_${volume_role}"
+script_dir=$(CDPATH= cd "$(dirname "$0")" && pwd)
+. "$script_dir/lib/vector-operation-lock.sh"
+vector_operation_lock_init
 private_archive_dir=
 private_archive_path=
+restart_qdrant=0
 cleanup() {
   status=$?
+  trap - EXIT HUP INT TERM
   if [ -n "${private_archive_dir:-}" ] && [ -d "${private_archive_dir:-}" ]; then
     rm -rf "$private_archive_dir"
   fi
   if [ "${restart_qdrant:-0}" -eq 1 ]; then
-    docker compose --project-name "$project_name" start qdrant >/dev/null
+    if ! docker compose --project-name "$project_name" start qdrant >/dev/null; then
+      echo "Unable to restart Qdrant after restore" >&2
+      [ "$status" -ne 0 ] || status=1
+    fi
+  fi
+  if ! release_vector_operation_lock; then
+    [ "$status" -ne 0 ] || status=1
   fi
   exit "$status"
 }
@@ -219,11 +230,11 @@ validate_archive_paths
 validate_archive_types
 validate_archive_manifest
 
+acquire_vector_operation_lock
 volume_name=$(resolve_volume)
 validate_volume_metadata "$volume_name"
 
 running_container=$(docker compose --project-name "$project_name" ps --status running -q qdrant)
-restart_qdrant=0
 
 if [ -n "$running_container" ]; then
   docker compose --project-name "$project_name" stop qdrant >/dev/null