feat: pin sessions to workspace revisions

backend/test/routes-sessions.test.ts

@@ -1,4 +1,4 @@
-import { test, expect } from "vitest";
+import { test, expect, vi } from "vitest";
 import { spawn as nodeSpawn } from "node:child_process";
 import path from "node:path";
 import os from "node:os";
@@ -148,6 +148,44 @@ test("new sessions are created through the authenticated principal, not a client
   expect(principal).toMatchObject({ issuer: "portal", subject: "alice" });
 });
 
+test("creates a session from the active immutable workspace revision", async () => {
+  const sessionNew = vi.fn(async () => ({ id: "pinned" }));
+  const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
+    thtRunner: { sessionNew, searchPack: async () => {} } as any,
+    readiness: { ensure: async () => ({ ok: true }) } as any,
+    mgr: {
+      get: () => undefined,
+      createFor: () => ({ bridge: { onClientEvent: () => {} } }),
+      configure: async () => {},
+      start: () => {},
+    } as any,
+    getSettings: () => ({ provider: "zai", model: "glm-5.2", thinking: "low" }) as any,
+    listModels: async () => [{ provider: "zai", id: "glm-5.2", name: "GLM 5.2", reasoning: true }],
+    workspaceRegistry: {
+      read: vi.fn(async () => ({
+        workspace: {
+          workspace: { schema_version: 2, id: "psd-clinical", name: "PSD", language: "it" },
+          dwh: {}, semantic_index: {}, llm_policy: { allowed: ["zai/glm-5.2"] },
+        },
+        revision: {
+          id: "psd-clinical", commit: "a".repeat(40), blob: "b".repeat(40),
+          snapshotPath: "/data/workspace-registry/snapshots/abc/psd-clinical.yaml", state: "operational",
+        },
+      })),
+    } as any,
+  });
+
+  await app.inject({
+    method: "POST", url: "/sessions",
+    payload: { question: "q", workspaceId: "psd-clinical", provider: "zai", model: "glm-5.2", thinking: "low" },
+  });
+
+  expect(sessionNew).toHaveBeenCalledWith(expect.objectContaining({
+    workspaceConfigPath: "/data/workspace-registry/snapshots/abc/psd-clinical.yaml",
+    workspaceId: "psd-clinical", workspaceRevision: "a".repeat(40),
+  }));
+});
+
 test("POST /sessions usa i settings (workspace/provider/model/thinking) e crea+avvia", async () => {
   const modelKey = path.join(os.tmpdir(), `thoth-model-key-${process.pid}`);
   writeFileSync(modelKey, "test-model-key", { mode: 0o600 });
@@ -171,7 +209,7 @@ test("POST /sessions usa i settings (workspace/provider/model/thinking) e crea+a
   });
   const created = await app.inject({ method: "POST", url: "/sessions", payload: { question: "q" } });
   expect(created.json()).toEqual({ id: "s1" });
-  expect(sessionNewArg.workspace).toBe("w");
+  expect(sessionNewArg.workspaceConfigPath).toBe("w");
   expect(sessionNewArg.provider).toBe("zai");
   expect(sessionNewArg.model).toBe("glm-5.2");
   expect(sessionNewArg.thinking).toBe("high");
@@ -373,6 +411,78 @@ test("POST /sessions/:id/resume configura Pi con il thinking persistito", async
   expect(configured.thinking).toBe("medium");
 });
 
+test("POST /sessions/:id/resume uses the manifest's retained workspace revision", async () => {
+  const reopenSession = vi.fn(async () => {});
+  const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
+    mgr: {
+      get: () => undefined,
+      createFor: () => ({ bridge: { onClientEvent: () => {} } }),
+      configure: async () => {}, start: () => {},
+    } as any,
+    thtRunner: {
+      sessionShow: async () => ({
+        status: "open", archived: false, workspace_id: "psd-clinical", workspace_revision: "a".repeat(40),
+      }),
+      reopenSession,
+    } as any,
+    readiness: { ensure: async () => ({ ok: true }) } as any,
+    getSettings: () => ({ workspace: "legacy" }) as any,
+    workspaceRegistry: {
+      readPinned: vi.fn(async () => ({
+        workspace: { workspace: { id: "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",
+        },
+      })),
+    } as any,
+  });
+
+  const response = await app.inject({ method: "POST", url: "/sessions/pinned/resume" });
+
+  expect(response.statusCode).toBe(200);
+  expect(reopenSession).toHaveBeenCalledWith(
+    "pinned", "/data/workspace-registry/snapshots/aaaaaaaa/psd-clinical.yaml",
+  );
+});
+
+test("POST /sessions/:id/resume returns a sanitized error when its retained revision is unavailable", async () => {
+  const rawFailure = "cannot read /data/workspace-registry/snapshots/secret-revision";
+  const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
+    thtRunner: {
+      sessionShow: async () => ({
+        status: "open", archived: false, workspace_id: "psd-clinical", workspace_revision: "a".repeat(40),
+      }),
+    } as any,
+    getSettings: () => ({ workspace: "legacy" }) as any,
+    workspaceRegistry: { readPinned: async () => { throw new Error(rawFailure); } } as any,
+  });
+
+  const response = await app.inject({ method: "POST", url: "/sessions/pinned/resume" });
+
+  expect(response.statusCode).toBe(409);
+  expect(response.body).not.toContain(rawFailure);
+  expect(response.json()).toMatchObject({ code: "workspace_revision_unavailable" });
+});
+
+test("GET /sessions/:id warns when a legacy manifest has no workspace revision", async () => {
+  const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
+    mgr: {
+      get: () => undefined,
+      createFor: () => ({ bridge: { onClientEvent: () => {} } }),
+      configure: async () => {}, start: () => {},
+    } as any,
+    thtRunner: { sessionShow: async () => ({ status: "open", archived: false }), reopenSession: async () => {} } as any,
+    readiness: { ensure: async () => ({ ok: true }) } as any,
+    getSettings: () => ({ workspace: "legacy" }) as any,
+  });
+
+  const response = await app.inject({ method: "GET", url: "/sessions/legacy" });
+
+  expect(response.statusCode).toBe(200);
+  expect(response.json()).toMatchObject({ warning: expect.stringMatching(/legacy/i) });
+});
+
 test("POST /sessions/:id/resume usa il thinking globale se manca nel manifest", async () => {
   let configured: any;
   const bridge = { onClientEvent: () => {}, emitClientEvent: () => {} };