fix(compaction): do not inherit extras after a failed /clear

Stamp last workdir and session id only after a successful rebuild so
a failed factory cannot make the retry look like the same session.

Author: TheGreatAxios

src/session/assemble-runtime.test.ts

@@ -292,24 +292,31 @@ async function withAssembledDirector(
     getRecords: () => readonly ManifestRecord[];
     directorHolder: { instance?: ChatDirector };
     wiring?: Partial<ChatAgentWiring>;
+    beforeCreateSessionStores?: () => void;
+    onReadManifestHistory?: (limit: number) => void;
   },
   run: (buildAgent: () => Promise<unknown>) => Promise<void>,
 ): Promise<void> {
   const fakeAgent = { close: async () => undefined } as unknown as Agent;
   const fakeStorage = {
     readBlob: async () => new Uint8Array(),
-    readManifestHistory: async (limit: number) =>
-      input.getRecords().slice(0, limit),
+    readManifestHistory: async (limit: number) => {
+      input.onReadManifestHistory?.(limit);
+      return input.getRecords().slice(0, limit);
+    },
   } as unknown as ContextStore;
 
   await withMockedModuleDuring(
     import.meta.resolve("./optimized-context-store.js"),
     (real: typeof import("./optimized-context-store.js")) => ({
       ...real,
-      createSessionStores: async () => ({
-        storage: fakeStorage,
-        audit: stubAuditStore(),
-      }),
+      createSessionStores: async () => {
+        input.beforeCreateSessionStores?.();
+        return {
+          storage: fakeStorage,
+          audit: stubAuditStore(),
+        };
+      },
     }),
     async () => {
       await withMockedModuleDuring(
@@ -534,20 +541,68 @@ describe("assembleChatAgent", () => {
     );
   });
 
+  test("failed /clear rebuild then retry on a new identity does not inherit extraInstructions", async () => {
+    let records: ManifestRecord[] = [
+      pruningExtrasRecord("keep the auth discussion"),
+    ];
+    let workdir = "/session-a";
+    let sessionId = "session-a";
+    let failStores = false;
+    const directorHolder: { instance?: ChatDirector } = {};
+
+    await withAssembledDirector(
+      {
+        getRecords: () => records,
+        directorHolder,
+        wiring: {
+          getWorkdir: () => workdir,
+          getSessionId: () => sessionId,
+        },
+        beforeCreateSessionStores: () => {
+          if (failStores) throw new Error("store rebuild failed");
+        },
+      },
+      async (buildAgent) => {
+        await buildAgent();
+        expect(directorHolder.instance?.getCompactInstructions()).toBe(
+          "keep the auth discussion",
+        );
+        records = [];
+        workdir = "/session-b";
+        sessionId = "session-b";
+        failStores = true;
+        await expect(buildAgent()).rejects.toThrow("store rebuild failed");
+        failStores = false;
+        await buildAgent();
+        expect(
+          directorHolder.instance?.getCompactInstructions(),
+        ).toBeUndefined();
+      },
+    );
+  });
+
   test("cold resume restores extraInstructions beyond 32 later cycles", async () => {
     const records: ManifestRecord[] = [
       ...Array.from({ length: 32 }, () => laterManifestRecord()),
       pruningExtrasRecord("keep the auth discussion"),
     ];
     const directorHolder: { instance?: ChatDirector } = {};
+    const limits: number[] = [];
 
     await withAssembledDirector(
-      { getRecords: () => records, directorHolder },
+      {
+        getRecords: () => records,
+        directorHolder,
+        onReadManifestHistory: (limit) => {
+          limits.push(limit);
+        },
+      },
       async (buildAgent) => {
         await buildAgent();
         expect(directorHolder.instance?.getCompactInstructions()).toBe(
           "keep the auth discussion",
         );
+        expect(limits).toEqual([32, 64]);
       },
     );
   });

src/session/assemble-runtime.ts

@@ -610,8 +610,10 @@ export function assembleChatAgent(wiring: ChatAgentWiring): AssembledChatAgent {
     inheritFromPrev =
       lastWorkdir === undefined ||
       (lastWorkdir === workdir && lastSessionId === sessionId);
-    lastWorkdir = workdir;
-    lastSessionId = sessionId;
+    // Do not stamp last* until this build succeeds. A failed /clear factory
+    // would otherwise make the retry look like the same session and inherit
+    // extras from the previous director / sticky store snapshot.
+    if (!inheritFromPrev) stickyFromStore = undefined;
     const { storage, audit } = await createSessionStores(workdir);
     // Primary-only evidence archive. Workers never pass evidenceArchiveHolder, so
     // they keep plain storage and omit admission / authorize recording wraps.
@@ -721,6 +723,8 @@ export function assembleChatAgent(wiring: ChatAgentWiring): AssembledChatAgent {
         ? agent
         : createPrimaryDeliveryAdmission(agent, primaryArchive);
     wiring.onBuilt(admittedAgent, storageForAgent);
+    lastWorkdir = workdir;
+    lastSessionId = sessionId;
     return admittedAgent;
   };