fix(app): source composer cwd from agent state, not draft hook

The GitHub picker showed "No results found." for any running agent after
the first message was sent. useAgentInputDraft owned a local cwd state
that clear("sent") wiped to "", so the composer read cwd: "" even though
the agent's real cwd was correct on the wire.

Drop cwd ownership from the hook. Composer takes cwd as a prop sourced
by the parent — agentState.cwd for running agents, composerState.workingDir
for drafts, sourceDirectory for setup flows. The hook now persists only
{text, attachments}. Legacy persisted drafts with a cwd field still
hydrate; tagged COMPAT(draft-cwd) for removal after 2026-11-09.

Also moves attachment pills back inside the composer's bordered surface
via a new attachmentSlot prop on MessageInput, and shrinks pill height
from 48 to 32 — the subagents-track tuck previously had attachments
floating between it and the input.

Adds one Playwright spec asserting the draft-create-agent path submits
the workspace cwd.

packages/app/src/stores/draft-store.lifecycle.test.ts

@@ -7,19 +7,19 @@ describe("draft-store lifecycle", () => {
     const nowMs = 1_000_000;
     const drafts = {
       oldSent: {
-        input: { text: "", attachments: [], cwd: "" },
+        input: { text: "", attachments: [] },
         lifecycle: "sent" as const,
         updatedAt: 0,
         version: 2,
       },
       recentAbandoned: {
-        input: { text: "", attachments: [], cwd: "" },
+        input: { text: "", attachments: [] },
         lifecycle: "abandoned" as const,
         updatedAt: nowMs + 2 * 60 * 1000,
         version: 2,
       },
       active: {
-        input: { text: "a", attachments: [], cwd: "/repo" },
+        input: { text: "a", attachments: [] },
         lifecycle: "active" as const,
         updatedAt: 0,
         version: 1,
@@ -53,7 +53,6 @@ describe("draft-store lifecycle", () => {
               },
             },
           ],
-          cwd: "/repo",
         },
         lifecycle: "active",
         updatedAt: 1,
@@ -64,7 +63,7 @@ describe("draft-store lifecycle", () => {
     });
 
     expect(cleared).toEqual({
-      input: { text: "", attachments: [], cwd: "" },
+      input: { text: "", attachments: [] },
       lifecycle: "sent",
       updatedAt: 2,
       version: 2,

packages/app/src/stores/draft-store.migration.test.ts

@@ -87,11 +87,10 @@ describe("draft-store migration", () => {
           },
         },
       ],
-      cwd: "",
     });
   });
 
-  it("is idempotent for already-migrated shapes", async () => {
+  it("hydrates old persisted drafts that still include cwd", async () => {
     const original = {
       drafts: {
         "agent:server:agent": {
@@ -123,6 +122,21 @@ describe("draft-store migration", () => {
     const twice = await __draftStoreTestUtils.migratePersistedState(once);
 
     expect(twice).toEqual(once);
+    expect(twice.drafts["agent:server:agent"]?.input).toEqual({
+      text: "hello",
+      attachments: [
+        {
+          kind: "image",
+          metadata: {
+            id: "att-1",
+            mimeType: "image/jpeg",
+            storageType: "web-indexeddb",
+            storageKey: "att-1",
+            createdAt: 1700000000000,
+          },
+        },
+      ],
+    });
   });
 
   it("rejects workspace review attachments from migrated draft attachments", async () => {
@@ -132,7 +146,6 @@ describe("draft-store migration", () => {
           input: {
             text: "hello",
             attachments: [workspaceReviewAttachment()],
-            cwd: "/repo",
           },
           lifecycle: "active",
           updatedAt: 1700000000001,

packages/app/src/stores/draft-store.ts

@@ -24,7 +24,6 @@ type PersistedDraftImage = AttachmentMetadata | LegacyDraftImage;
 export interface DraftInput {
   text: string;
   attachments: UserComposerAttachment[];
-  cwd: string;
 }
 
 export type DraftLifecycleState = "active" | "abandoned" | "sent";
@@ -45,10 +44,7 @@ interface DraftStoreState {
 
 interface DraftStoreActions {
   getDraftInput: (draftKey: string) => DraftInput | undefined;
-  hydrateDraftInput: (input: {
-    draftKey: string;
-    initialCwd?: string;
-  }) => Promise<DraftInput | undefined>;
+  hydrateDraftInput: (input: { draftKey: string }) => Promise<DraftInput | undefined>;
   saveDraftInput: (input: { draftKey: string; draft: DraftInput }) => void;
   markDraftLifecycle: (input: { draftKey: string; lifecycle: DraftLifecycleState }) => void;
   clearDraftInput: (input: {
@@ -76,7 +72,6 @@ function createDraftRecord(input: {
     input: {
       text: input.draft.text,
       attachments: input.draft.attachments.map(normalizeComposerAttachment),
-      cwd: input.draft.cwd,
     },
     lifecycle: input.lifecycle,
     updatedAt: Date.now(),
@@ -181,11 +176,11 @@ function isCanonicalDraftInput(value: unknown): value is CanonicalDraftInput {
     return false;
   }
   const input = value as Record<string, unknown>;
+  // COMPAT(draft-cwd): accept legacy persisted drafts that include cwd. Stop accepting after 2026-11-09.
   return (
     typeof input.text === "string" &&
     Array.isArray(input.attachments) &&
-    input.attachments.every(isUserComposerAttachment) &&
-    typeof input.cwd === "string"
+    input.attachments.every(isUserComposerAttachment)
   );
 }
 
@@ -202,7 +197,6 @@ function toDraftInputIfReady(record: DraftRecord | null | undefined): DraftInput
   return {
     text: record.input.text,
     attachments: record.input.attachments.map(normalizeComposerAttachment),
-    cwd: record.input.cwd,
   };
 }
 
@@ -262,7 +256,7 @@ function applyClearDraftRecord(input: {
 
   return {
     ...input.record,
-    input: { text: "", attachments: [], cwd: "" },
+    input: { text: "", attachments: [] },
     lifecycle: input.lifecycle,
     updatedAt: input.nowMs,
     version: input.record.version + 1,
@@ -417,10 +411,7 @@ async function migrateLegacyImages(
   return migrated.filter((entry): entry is AttachmentMetadata => entry !== null);
 }
 
-async function migrateDraftInput(input: {
-  rawInput: unknown;
-  initialCwd?: string;
-}): Promise<CanonicalDraftInput> {
+async function migrateDraftInput(input: { rawInput: unknown }): Promise<CanonicalDraftInput> {
   const rawInput =
     input.rawInput && typeof input.rawInput === "object"
       ? (input.rawInput as Record<string, unknown>)
@@ -440,7 +431,6 @@ async function migrateDraftInput(input: {
   return {
     text: typeof rawInput.text === "string" ? rawInput.text : "",
     attachments: [...attachments, ...legacyImagesToAttachments(migratedImages)],
-    cwd: typeof rawInput.cwd === "string" ? rawInput.cwd : (input.initialCwd ?? ""),
   };
 }
 
@@ -505,7 +495,7 @@ export const useDraftStore = create<DraftStore>()(
         return toDraftInputIfReady(record);
       },
 
-      hydrateDraftInput: async ({ draftKey, initialCwd }) => {
+      hydrateDraftInput: async ({ draftKey }) => {
         const current = get().drafts[draftKey];
         if (!current) {
           return undefined;
@@ -520,7 +510,6 @@ export const useDraftStore = create<DraftStore>()(
 
         const migratedDraft = await migrateDraftInput({
           rawInput: current.input,
-          initialCwd,
         });
 
         set((state) => {