feat: establish unified administration and model context baseline

frontend/src/api/sessions.test.ts

@@ -232,11 +232,16 @@ test("getMe fetches the typed authenticated principal", async () => {
 });
 
 test("resumeSession returns the typed runtime disposition", async () => {
-  server.use(http.post("/api/sessions/s1/resume", () =>
-    HttpResponse.json({ id: "s1", alreadyActive: false })));
+  workspacePreferences.save({ workspaceId: "different-workspace", provider: "local", model: "qwen", thinking: "medium" });
+  let body: unknown;
+  server.use(http.post("/api/sessions/s1/resume", async ({ request }) => {
+    body = await request.json();
+    return HttpResponse.json({ id: "s1", alreadyActive: false });
+  }));
 
   const result: { id: string; alreadyActive: boolean } = await resumeSession("s1");
   expect(result).toEqual({ id: "s1", alreadyActive: false });
+  expect(body).toEqual({ provider: "local", model: "qwen" });
 });
 
 test("renameSession POSTs {name}", async () => {

frontend/src/api/sessions.ts

@@ -26,11 +26,12 @@ async function selectedPreferences(precondition?: AuthOperationPrecondition): Pr
   // application memory from the installation defaults once, then keep choices ephemeral.
   const legacy = await getSettings();
   requireAuthOperationPrecondition(precondition);
+  const latest = workspacePreferences.load();
   return workspacePreferences.save({
-    workspaceId: saved.workspaceId ?? legacy.workspace,
-    provider: saved.provider ?? legacy.provider,
-    model: saved.model ?? legacy.model,
-    thinking: saved.thinking ?? legacy.thinking,
+    workspaceId: latest.workspaceId ?? legacy.workspace,
+    provider: latest.provider ?? legacy.provider,
+    model: latest.model ?? legacy.model,
+    thinking: latest.thinking ?? legacy.thinking,
   });
 }
 
@@ -139,8 +140,20 @@ export const postSteer = (id: string, text: string) =>
 export const closeSession = (id: string) =>
   apiFetch<void>(`/sessions/${id}/close`, { method: "POST" });
 
-export const resumeSession = (id: string) =>
-  apiFetch<ResumeSessionResult>(`/sessions/${id}/resume`, { method: "POST" });
+export async function resumeSession(id: string) {
+  const operation = captureAuthOperation();
+  const precondition = operation ? {
+    operation,
+    isCurrent: () => isAuthOperationCurrent(operation, { sessionId: null, disposalEpoch: operation.disposalEpoch }),
+  } : undefined;
+  const selected = await selectedPreferences(precondition);
+  requireAuthOperationPrecondition(precondition);
+  return apiFetch<ResumeSessionResult>(`/sessions/${id}/resume`, {
+    method: "POST",
+    // The workspace is owned by the persisted session, never by this request.
+    body: JSON.stringify({ provider: selected.provider, model: selected.model }),
+  });
+}
 
 export const renameSession = (id: string, name: string) =>
   apiFetch<void>(`/sessions/${id}/rename`, { method: "POST", body: JSON.stringify({ name }) });

frontend/src/api/types.ts

@@ -160,6 +160,8 @@ export interface Principal {
 export interface ResumeSessionResult {
   id: string;
   alreadyActive: boolean;
+  /** The session's pinned workspace; never supplied by the client. */
+  workspaceId?: string;
 }
 
 export interface SessionDocument {