feat: pin sessions to workspace revisions

.superpowers/sdd/2026-08-03-git-workspace-registry/task-7-report.md

@@ -32,3 +32,29 @@ The unscoped backend suite was also run. The Task 7 code regressions in `test/th
 were fixed; the remaining failures were existing sandbox restrictions on tests that listen on
 `127.0.0.1` (`listen EPERM: operation not permitted` in SSE/e2e health tests), not application
 assertions.
+
+## Review fixes — round 1
+
+- Every new session now resolves `workspaceId` through the registry; an omitted value uses the
+  configured installation default and persists both the resolved ID and revision. Callers cannot
+  bypass revision pinning by supplying a workspace ID.
+- Browser-local preferences now migrate once from the read-only legacy settings response and hold
+  workspace, provider, model, and thinking. Session creation includes those selections, including
+  direct entry points that run before the composer mounts. The frontend no longer `PUT`s shared
+  settings.
+- The settings compatibility endpoint honors a stored installation workspace before falling back
+  to the first workspace configuration.
+- Resume rejects finalized and archived sessions before looking up any pinned snapshot, preserving
+  the read-only response even when a historical snapshot is unavailable.
+
+### Review verification
+
+- RED: the added backend tests failed for omitted-default pinning, read-only resume ordering, and
+  stored-default precedence; the added frontend preference tests failed because preferences were
+  neither stored nor included in session requests.
+- GREEN: `npx vitest run test/tht-runner.test.ts test/routes-sessions.test.ts test/routes-settings.test.ts && npx tsc --noEmit -p .`
+  — 100 tests passed with a clean type check.
+- GREEN: `npx vitest run && npx tsc -b` — 332 frontend tests passed with a clean type check.
+- GREEN: `THT_HOME=/private/tmp/thothii-task7-home .venv/bin/pytest tests/test_session_documents.py tests/test_session_mutations.py -q`
+  — 22 tests passed (one existing testcontainers deprecation warning).
+- `git diff --check` completed cleanly.

backend/src/routes/sessions.ts

@@ -207,29 +207,34 @@ export function sessionRoutes(
     let s: Settings;
     try { s = await d.getSettings(principal); } catch { return storageFailure(reply); }
     const runner = runnerFor(principal);
-    let workspaceConfigPath = s.workspace;
+    const requestedWorkspaceId = b.workspaceId ?? s.workspace;
+    if (!requestedWorkspaceId) {
+      return reply.code(409).send({
+        error: WORKSPACE_REVISION_UNAVAILABLE_MESSAGE,
+        code: "workspace_revision_unavailable",
+      });
+    }
+    let workspaceConfigPath: string | undefined;
     let workspaceId: string | undefined;
     let workspaceRevision: string | undefined;
     let allowedModels: readonly string[] | undefined;
-    if (b.workspaceId) {
+    try {
-      try {
+      const resolved = await d.workspaceRegistry.read(requestedWorkspaceId);
-        const resolved = await d.workspaceRegistry.read(b.workspaceId);
+      if (resolved.revision.state !== "operational") {
-        if (resolved.revision.state !== "operational") {
-          return reply.code(409).send({
-            error: WORKSPACE_REVISION_UNAVAILABLE_MESSAGE,
-            code: "workspace_revision_unavailable",
-          });
-        }
-        workspaceConfigPath = resolved.revision.snapshotPath;
-        workspaceId = resolved.revision.id;
-        workspaceRevision = resolved.revision.commit;
-        allowedModels = resolved.workspace.llm_policy.allowed;
-      } catch {
         return reply.code(409).send({
           error: WORKSPACE_REVISION_UNAVAILABLE_MESSAGE,
           code: "workspace_revision_unavailable",
         });
       }
+      workspaceConfigPath = resolved.revision.snapshotPath;
+      workspaceId = resolved.revision.id;
+      workspaceRevision = resolved.revision.commit;
+      allowedModels = resolved.workspace.llm_policy.allowed;
+    } catch {
+      return reply.code(409).send({
+        error: WORKSPACE_REVISION_UNAVAILABLE_MESSAGE,
+        code: "workspace_revision_unavailable",
+      });
     }
     const provider = b.provider ?? s.provider;
     const model = b.model ?? s.model;
@@ -378,6 +383,11 @@ export function sessionRoutes(
       } catch { return storageFailure(reply); }
       if (!manifest) return reply.code(404).send({ error: "session not found" });
       const runner = runnerFor(principal);
+      // Read-only contract FIRST: finalized or archived sessions never attempt compatibility
+      // resolution, even when their historical snapshot was subsequently pruned.
+      if (manifest?.status === "finalized" || manifest?.archived) {
+        return reply.code(409).send({ error: "sessione in sola lettura (finalizzata o archiviata)" });
+      }
       const saved = manifest as {
         provider?: string; model?: string; thinking?: string;
         workspace_id?: string; workspace_revision?: string;
@@ -397,11 +407,6 @@ export function sessionRoutes(
           });
         }
       }
-      // Read-only contract FIRST: a finalized/archived session must refuse resume even
-      // when a lingering runtime still looks active — the manifest is the truth.
-      if (manifest?.status === "finalized" || manifest?.archived) {
-        return reply.code(409).send({ error: "sessione in sola lettura (finalizzata o archiviata)" });
-      }
       // This check belongs inside the per-session lock: a preceding cold Resume may have
       // installed a running runtime while this request was waiting.
       const existing = d.mgr.get(id);

backend/src/routes/settings.ts

@@ -9,7 +9,7 @@ import type { PrincipalContext } from "../auth/principal.js";
 export function effectiveSettings(cfg: AppConfig, stored: Settings): Settings {
   const workspaces = listWorkspaces(cfg.harnessDir);
   return {
-    workspace: workspaces[0]?.name ?? stored.workspace,
+    workspace: stored.workspace ?? workspaces[0]?.name,
     provider: cfg.defaults.provider ?? stored.provider,
     model: cfg.defaults.model ?? stored.model,
     thinking: cfg.defaults.thinking ?? stored.thinking,

backend/test/routes-sessions.test.ts

@@ -3,13 +3,31 @@ import { spawn as nodeSpawn } from "node:child_process";
 import path from "node:path";
 import os from "node:os";
 import { chmodSync, unlinkSync, writeFileSync } from "node:fs";
-import { buildApp } from "../src/app.js";
+import { buildApp as buildRealApp } from "../src/app.js";
 import { loadConfig } from "../src/config.js";
 import { SseHub } from "../src/sse/sse-hub.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");
 
+const defaultWorkspaceRegistry = {
+  read: vi.fn(async (id: string) => ({
+    workspace: {
+      llm_policy: {
+        allowed: ["zai/glm-5.2", "deepseek/deepseek-v4-pro", "local-qwen/qwen3.6-35b-a3b"],
+      },
+    },
+    revision: {
+      id, commit: "e".repeat(40), blob: "f".repeat(40),
+      snapshotPath: `/data/workspace-registry/snapshots/${"e".repeat(40)}/${id}.yaml`, state: "operational",
+    },
+  })),
+};
+
+function buildApp(config: Parameters<typeof buildRealApp>[0], deps: Record<string, unknown> = {}) {
+  return buildRealApp(config, { workspaceRegistry: defaultWorkspaceRegistry as any, ...deps } as any);
+}
+
 function mutApp(thtRunner: any) {
   return buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
     thtRunner: { ollamaEnsure: async () => ({ ok: true }), ...thtRunner },
@@ -186,6 +204,35 @@ test("creates a session from the active immutable workspace revision", async ()
   }));
 });
 
+test("creates a session from the configured default workspace revision when workspaceId is omitted", async () => {
+  const sessionNew = vi.fn(async () => ({ id: "default-pinned" }));
+  const registry = {
+    read: vi.fn(async (id: string) => ({
+      workspace: { llm_policy: { allowed: ["zai/glm-5.2"] } },
+      revision: {
+        id, commit: "c".repeat(40), blob: "d".repeat(40),
+        snapshotPath: `/data/workspace-registry/snapshots/${"c".repeat(40)}/${id}.yaml`, state: "operational",
+      },
+    })),
+  };
+  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: () => ({ workspace: "psd-clinical", 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: registry as any,
+  });
+
+  await app.inject({ method: "POST", url: "/sessions", payload: { question: "q" } });
+
+  expect(registry.read).toHaveBeenCalledWith("psd-clinical");
+  expect(sessionNew).toHaveBeenCalledWith(expect.objectContaining({
+    workspaceId: "psd-clinical", workspaceRevision: "c".repeat(40),
+    workspaceConfigPath: `/data/workspace-registry/snapshots/${"c".repeat(40)}/psd-clinical.yaml`,
+  }));
+});
+
 test("POST /sessions usa i settings (workspace/provider/model/thinking) e crea+avvia", async () => {
   const modelKey = path.join(os.tmpdir(), `thoth-model-key-${process.pid}`);
   writeFileSync(modelKey, "test-model-key", { mode: 0o600 });
@@ -209,7 +256,7 @@ 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.workspaceConfigPath).toBe("w");
+  expect(sessionNewArg.workspaceConfigPath).toContain(`/snapshots/${"e".repeat(40)}/w.yaml`);
   expect(sessionNewArg.provider).toBe("zai");
   expect(sessionNewArg.model).toBe("glm-5.2");
   expect(sessionNewArg.thinking).toBe("high");
@@ -465,6 +512,25 @@ 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 refuses a pinned finalized session before reading its snapshot", async () => {
+  const readPinned = vi.fn(async () => { throw new Error("must not resolve"); });
+  const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
+    thtRunner: {
+      sessionShow: async () => ({
+        status: "finalized", archived: false, workspace_id: "psd-clinical", workspace_revision: "a".repeat(40),
+      }),
+    } as any,
+    getSettings: () => ({ workspace: "legacy" }) as any,
+    workspaceRegistry: { readPinned } as any,
+  });
+
+  const response = await app.inject({ method: "POST", url: "/sessions/pinned-final/resume" });
+
+  expect(response.statusCode).toBe(409);
+  expect(response.json()).toMatchObject({ error: expect.stringMatching(/sola lettura/i) });
+  expect(readPinned).not.toHaveBeenCalled();
+});
+
 test("GET /sessions/:id warns when a legacy manifest has no workspace revision", async () => {
   const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
     mgr: {
@@ -1801,7 +1867,7 @@ 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(ensureWs).toBe("psd");
+  expect(ensureWs).toContain(`/snapshots/${"e".repeat(40)}/psd.yaml`);
 });
 
 test("POST /sessions rejects an unavailable saved model before persisting a session", async () => {
@@ -1842,7 +1908,7 @@ test("POST /sessions marks a persisted session failed when runtime construction
       sessionNew: async () => ({ id: "s-runtime-failure" }),
       failSession: async (id: string, workspace: string) => {
         expect(id).toBe("s-runtime-failure");
-        expect(workspace).toBe("psd");
+        expect(workspace).toContain(`/snapshots/${"e".repeat(40)}/psd.yaml`);
         failed += 1;
       },
     } as any,

backend/test/routes-settings.test.ts

@@ -31,6 +31,19 @@ test("GET /settings returns effective defaults (env provider/model/thinking, fir
   }
 });
 
+test("GET /settings uses the stored installation workspace default before the harness fallback", async () => {
+  const { app, dir } = appWithTmpSettings({});
+  try {
+    writeFileSync(join(dir, "settings.json"), JSON.stringify({ workspace: "psd-clinical" }));
+
+    const response = await app.inject({ method: "GET", url: "/settings" });
+
+    expect(response.json()).toMatchObject({ workspace: "psd-clinical" });
+  } finally {
+    rmSync(dir, { recursive: true, force: true });
+  }
+});
+
 test("PUT /settings does not persist personal workspace or LLM choices", async () => {
   const { app, dir } = appWithTmpSettings({ PI_PROVIDER: "zai", PI_MODEL: "glm-5.2", PI_THINKING: "medium" }, {
     listModels: async () => [{ provider: "zai", id: "glm-5.2", name: "GLM 5.2", reasoning: true }],

frontend/src/api/sessions.test.ts

@@ -6,16 +6,25 @@ import {
   deleteSession, getSessionDocuments,
 } from "./sessions";
 
-test("createSession POSTs only {question} and returns the id", async () => {
+test("createSession migrates legacy selections and POSTs browser preferences", async () => {
+  localStorage.clear();
   let body: unknown = null;
   server.use(
+    http.get("http://localhost:8787/settings", () => HttpResponse.json({
+      workspace: "psd-clinical", provider: "zai", model: "glm-5.2", thinking: "low",
+    })),
     http.post("http://localhost:8787/sessions", async ({ request }) => {
       body = await request.json();
       return HttpResponse.json({ id: "s1" });
     }),
   );
   expect(await createSession({ question: "q" })).toEqual({ id: "s1" });
-  expect(body).toEqual({ question: "q" });
+  expect(body).toEqual({
+    question: "q", workspaceId: "psd-clinical", provider: "zai", model: "glm-5.2", thinking: "low",
+  });
+  expect(JSON.parse(localStorage.getItem("thothii.workspace-registry.v1.preferences")!)).toEqual({
+    workspaceId: "psd-clinical", provider: "zai", model: "glm-5.2", thinking: "low",
+  });
 });
 
 test.each([202, 204])("prewarmRuntime accepts a body-less %s response", async (status) => {

frontend/src/api/sessions.ts

@@ -1,10 +1,34 @@
 import { apiFetch } from "./client";
+import { getSettings } from "./settings";
+import { workspacePreferences, type WorkspacePreference } from "../workspaces/preferences";
 import type {
   Principal, ResumeSessionResult, SessionScope, SessionSummary, SessionDocument, UiResponse,
 } from "./types";
 
-export const createSession = (i: { question: string; name?: string }) =>
+type NewSessionInput = { question: string; name?: string } & Partial<WorkspacePreference>;
-  apiFetch<{ id: string }>("/sessions", { method: "POST", body: JSON.stringify(i) });
+
+async function selectedPreferences(): Promise<WorkspacePreference> {
+  const saved = workspacePreferences.load();
+  if (saved.workspaceId && saved.provider && saved.model && saved.thinking) return saved;
+
+  // A direct new-session entry point can run before the composer has mounted. Seed its
+  // browser-local preferences from the legacy read-only defaults once, then keep them local.
+  const legacy = await getSettings();
+  return workspacePreferences.save({
+    workspaceId: saved.workspaceId ?? legacy.workspace,
+    provider: saved.provider ?? legacy.provider,
+    model: saved.model ?? legacy.model,
+    thinking: saved.thinking ?? legacy.thinking,
+  });
+}
+
+export async function createSession(i: NewSessionInput) {
+  const preferences = await selectedPreferences();
+  return apiFetch<{ id: string }>("/sessions", {
+    method: "POST",
+    body: JSON.stringify({ ...preferences, ...i }),
+  });
+}
 
 /** Best-effort warm-up; callers must not await it before showing the composer. */
 export const prewarmRuntime = () =>

frontend/src/shell/AppShell.new-session.test.tsx

@@ -13,6 +13,7 @@ function renderShell() {
 }
 
 beforeEach(() => {
+  localStorage.clear();
   FakeEventSource.instances = [];
   (globalThis as any).EventSource = FakeEventSource;
   useSessionStore.getState().resetSession();
@@ -121,8 +122,7 @@ test("a DWH-unreachable precheck shows a specific alert and preserves the questi
   expect(FakeEventSource.instances).toHaveLength(0);
 });
 
-test("model selector shows the three Pi-enabled models and persists the selected provider", async () => {
+test("model selector shows the three Pi-enabled models and stores the selected provider locally", async () => {
-  let saved: unknown;
   server.use(
     http.get("http://localhost:8787/settings", () => HttpResponse.json({
       workspace: "default", provider: "zai", model: "glm-5.2", thinking: "low",
@@ -132,11 +132,6 @@ test("model selector shows the three Pi-enabled models and persists the selected
       { provider: "deepseek", id: "deepseek-v4-flash", name: "DeepSeek V4 Flash", reasoning: true },
       { provider: "local-qwen", id: "qwen3.6-35b-a3b", name: "Qwen3.6 35B A3B Local", reasoning: false },
     ] })),
-    http.put("http://localhost:8787/settings", async ({ request }) => {
-      const body = await request.json() as Record<string, string>;
-      saved = body;
-      return HttpResponse.json(body);
-    }),
   );
   renderShell();
 
@@ -147,9 +142,10 @@ test("model selector shows the three Pi-enabled models and persists the selected
     ]);
   });
   await userEvent.selectOptions(select, "qwen3.6-35b-a3b");
-  await waitFor(() => expect(saved).toMatchObject({
+  await waitFor(() => expect(JSON.parse(localStorage.getItem("thothii.workspace-registry.v1.preferences")!))
-    provider: "local-qwen", model: "qwen3.6-35b-a3b",
+    .toEqual({
-  }));
+      workspaceId: "default", provider: "local-qwen", model: "qwen3.6-35b-a3b", thinking: "low",
+    }));
 });
 
 

frontend/src/shell/NewSessionDialog.test.tsx

@@ -27,9 +27,13 @@ test("the form has only a question field (no workspace/model/provider/thinking)"
   expect(screen.queryByLabelText(/thinking/i)).not.toBeInTheDocument();
 });
 
-test("submitting posts only { question } and calls onCreated", async () => {
+test("submitting includes browser-local migrated preferences and calls onCreated", async () => {
+  localStorage.clear();
   let body: unknown = null;
   server.use(
+    http.get("http://localhost:8787/settings", () => HttpResponse.json({
+      workspace: "default", provider: "zai", model: "glm-5.2", thinking: "low",
+    })),
     http.post("http://localhost:8787/sessions", async ({ request }) => {
       body = await request.json();
       return HttpResponse.json({ id: "s1" });
@@ -40,7 +44,10 @@ test("submitting posts only { question } and calls onCreated", async () => {
   await userEvent.type(await screen.findByLabelText(/question/i), "Quante vendite nel 2025?");
   await userEvent.click(screen.getByRole("button", { name: /^create$/i }));
 
-  await waitFor(() => expect(body).toEqual({ question: "Quante vendite nel 2025?" }));
+  await waitFor(() => expect(body).toEqual({
+    question: "Quante vendite nel 2025?",
+    workspaceId: "default", provider: "zai", model: "glm-5.2", thinking: "low",
+  }));
   await waitFor(() => expect(onCreated).toHaveBeenCalledWith("s1"));
 });
 

frontend/src/shell/SteerInput.test.tsx

@@ -8,6 +8,7 @@ import { useSessionStore } from "../store/sessionStore";
 import { ComposerFooter, ContextGauge, SteerInput } from "./SteerInput";
 
 beforeEach(() => {
+  localStorage.clear();
   server.use(
     http.post("http://localhost:8787/sessions/:id/steer", () =>
       new HttpResponse(null, { status: 204 }),
@@ -15,6 +16,25 @@ beforeEach(() => {
   );
 });
 
+test("new sessions send the browser-selected workspace, model, provider, and thinking", async () => {
+  let body: unknown;
+  localStorage.setItem("thothii.workspace-registry.v1.preferences", JSON.stringify({
+    workspaceId: "psd-clinical", provider: "zai", model: "glm-5.2", thinking: "high",
+  }));
+  server.use(http.post("http://localhost:8787/sessions", async ({ request }) => {
+    body = await request.json();
+    return HttpResponse.json({ id: "s1" });
+  }));
+  render(<SteerInput sessionId={null} />);
+
+  await userEvent.type(screen.getByRole("textbox", { name: /new question/i }), "q");
+  await userEvent.click(screen.getByRole("button", { name: /send/i }));
+
+  await waitFor(() => expect(body).toEqual({
+    question: "q", workspaceId: "psd-clinical", provider: "zai", model: "glm-5.2", thinking: "high",
+  }));
+});
+
 test("renders a text input and submit button", () => {
   render(<SteerInput sessionId="s1" />);
   expect(screen.getByRole("textbox")).toBeInTheDocument();

frontend/src/shell/SteerInput.tsx

@@ -1,13 +1,14 @@
 // frontend/src/shell/SteerInput.tsx
 import { useEffect, useRef, useState } from "react";
 import { CornerDownLeft } from "lucide-react";
-import { useQuery, useQueryClient } from "@tanstack/react-query";
+import { useQuery } from "@tanstack/react-query";
 import { postSteer, createSession } from "../api/sessions";
 import { ApiError } from "../api/client";
-import { getSettings, putSettings, type Settings } from "../api/settings";
+import { getSettings } from "../api/settings";
 import { listWorkspaces } from "../api/workspaces";
 import { listModels } from "../api/models";
 import { useSessionStore } from "../store/sessionStore";
+import { workspacePreferences, type WorkspacePreference } from "../workspaces/preferences";
 
 const THINKING_LEVELS = ["low", "medium", "high"] as const;
 
@@ -151,25 +152,33 @@ export function SteerInput({
 
 /**
  * Status strip beneath the composer. Left: the active workspace selector.
- * Right: live context usage plus model + thinking-level selectors (these replace
+ * Right: live context usage plus browser-local workspace/model/thinking selectors.
- * the old Settings dialog and persist through PUT /settings).
  */
 export function ComposerFooter() {
-  const qc = useQueryClient();
   const { data: settings } = useQuery({ queryKey: ["settings"], queryFn: getSettings });
   const { data: workspaces = [] } = useQuery({ queryKey: ["workspaces"], queryFn: listWorkspaces });
   const { data: modelsData } = useQuery({ queryKey: ["models"], queryFn: listModels });
   const models = modelsData?.models ?? [];
   const tokenUsage = useSessionStore((state) => state.tokenUsage);
+  const [preferences, setPreferences] = useState<WorkspacePreference>(() => workspacePreferences.load());
 
-  const workspace = settings?.workspace ?? "";
+  useEffect(() => {
-  const model = settings?.model ?? "";
+    if (!settings) return;
-  const thinking = settings?.thinking ?? "medium";
+    setPreferences(workspacePreferences.migrate({
+      workspaceId: settings.workspace,
+      provider: settings.provider,
+      model: settings.model,
+      thinking: settings.thinking,
+    }));
+  }, [settings]);
 
-  // PUT /settings replaces the whole object, so always send the merged settings.
+  const workspace = preferences.workspaceId ?? settings?.workspace ?? "";
-  async function update(patch: Partial<Settings>) {
+  const model = preferences.model ?? settings?.model ?? "";
-    await putSettings({ workspace, provider: settings?.provider, model, thinking, ...patch });
+  const thinking = preferences.thinking ?? settings?.thinking ?? "medium";
-    qc.invalidateQueries({ queryKey: ["settings"] });
+
+  function update(patch: WorkspacePreference) {
+    const next = workspacePreferences.save({ ...preferences, ...patch });
+    setPreferences(next);
   }
 
   function onModelChange(id: string) {
@@ -185,7 +194,7 @@ export function ComposerFooter() {
   return (
     <div className="flex items-center justify-between gap-2 border-t border-border/60 px-3 py-1.5">
       <div className="flex items-center gap-2">
-        <FooterSelect aria-label="Workspace" value={workspace} onChange={(v) => update({ workspace: v })}>
+        <FooterSelect aria-label="Workspace" value={workspace} onChange={(v) => update({ workspaceId: v })}>
           {workspaces.length === 0 ? (
             <option value="">— workspace —</option>
           ) : (

frontend/src/shell/f1-loop.test.tsx

@@ -9,6 +9,7 @@ import { App } from "../App";
 import { useSessionStore } from "../store/sessionStore";
 
 beforeEach(() => {
+  localStorage.clear();
   FakeEventSource.instances = [];
   (globalThis as any).EventSource = FakeEventSource;
   useSessionStore.getState().resetSession();
@@ -19,6 +20,9 @@ test("F1: create session -> widget via SSE -> respond -> POST /response", async
   server.use(
     http.post("http://localhost:8787/sessions", () => HttpResponse.json({ id: "s1" })),
     http.get("http://localhost:8787/sessions", () => HttpResponse.json([])),
+    http.get("http://localhost:8787/settings", () => HttpResponse.json({
+      workspace: "default", provider: "zai", model: "glm-5.2", thinking: "low",
+    })),
     http.get("http://localhost:8787/workspaces", () =>
       HttpResponse.json([{ name: "default", file: "default.db" }]),
     ),

frontend/src/workspaces/preferences.test.ts

@@ -0,0 +1,15 @@
+import { expect, test } from "vitest";
+import { workspacePreferences } from "./preferences";
+
+test("migrates legacy selections once and keeps later browser choices", () => {
+  localStorage.clear();
+
+  expect(workspacePreferences.migrate({
+    workspaceId: "psd-clinical", provider: "zai", model: "glm-5.2", thinking: "medium",
+  })).toMatchObject({ workspaceId: "psd-clinical", model: "glm-5.2" });
+  workspacePreferences.save({ workspaceId: "research", provider: "deepseek", model: "deepseek-v4-pro", thinking: "high" });
+
+  expect(workspacePreferences.migrate({ workspaceId: "legacy" })).toMatchObject({
+    workspaceId: "research", provider: "deepseek", model: "deepseek-v4-pro", thinking: "high",
+  });
+});

frontend/src/workspaces/preferences.ts

@@ -0,0 +1,40 @@
+export interface WorkspacePreference {
+  workspaceId?: string;
+  provider?: string;
+  model?: string;
+  thinking?: string;
+}
+
+const STORAGE_KEY = "thothii.workspace-registry.v1.preferences";
+
+function storage(): Storage | undefined {
+  try { return window.localStorage; } catch { return undefined; }
+}
+
+function parse(raw: string | null): WorkspacePreference | undefined {
+  if (raw === null) return undefined;
+  try {
+    const value = JSON.parse(raw);
+    return value && typeof value === "object" && !Array.isArray(value) ? value as WorkspacePreference : undefined;
+  } catch {
+    return undefined;
+  }
+}
+
+/** Anonymous, non-secret browser choices for the workspace session composer. */
+export const workspacePreferences = {
+  load(): WorkspacePreference {
+    return parse(storage()?.getItem(STORAGE_KEY) ?? null) ?? {};
+  },
+
+  save(value: WorkspacePreference): WorkspacePreference {
+    try { storage()?.setItem(STORAGE_KEY, JSON.stringify(value)); } catch { /* storage is optional */ }
+    return value;
+  },
+
+  /** Copy the pre-local-storage server values only when this browser has no saved choice. */
+  migrate(legacy: WorkspacePreference): WorkspacePreference {
+    const current = storage()?.getItem(STORAGE_KEY);
+    return current === null || current === undefined ? this.save(legacy) : this.load();
+  },
+};