P4-A: commande WS answer — répondre aux dialogues sans clavier

Nouvelle commande WS de haut niveau `answer {channel, action, optionN?}`
traduite côté serveur en keystrokes (chiffre+Entrée / Entrée / Esc) et
validée contre le dialogue courant du tracker (anti-frappe fantôme mobile).

- protocol.ts : message `answer` + validation parseClientMessage + ErrorCode INVALID_ANSWER
- pty-manager.answer() : mappe l'intention en write PTY, réutilise le modèle mono-utilisateur
- gateway : case `answer` (NOT_CONTROLLING / SESSION_EXITED / INVALID_ANSWER)
- web : Attachment.answer(), DialogPrompt.vue (attache interactive légère sink no-op),
  intégré dans SessionView, SessionsListView, WorktreeCard + i18n en/fr
- tests : parseClientMessage (answer valide/malformé + fuzz), pty-manager.answer (163 verts)

packages/shared/src/protocol.ts

@@ -166,6 +166,10 @@ export type ClientMessage =
   | { type: 'attach'; sessionId: string; mode: 'interactive' | 'observer'; cols: number; rows: number }
   | { type: 'detach'; channel: number }
   | { type: 'stdin'; channel: number; data: string }
+  // P4-A : répondre à un dialogue Claude sans clavier. Le serveur traduit l'intention
+  // en keystrokes (chiffre+Entrée pour 'select', Entrée pour 'confirm', Esc pour 'deny')
+  // et valide l'option contre le dialogue courant (anti-frappe fantôme mobile).
+  | { type: 'answer'; channel: number; action: 'select' | 'confirm' | 'deny'; optionN?: number }
   | { type: 'resize'; channel: number; cols: number; rows: number }
   | { type: 'ack'; channel: number; bytes: number }
   | { type: 'sub'; topics: Array<'sessions' | 'worktrees'> }
@@ -193,6 +197,7 @@ export type ErrorCode =
   | 'NOT_ATTACHED'
   | 'NOT_CONTROLLING'
   | 'SESSION_EXITED'
+  | 'INVALID_ANSWER'
   | 'INTERNAL';
 
 export function parseClientMessage(raw: string): ClientMessage | null {
@@ -220,6 +225,16 @@ export function parseClientMessage(raw: string): ClientMessage | null {
       return isU32(m.channel) && typeof m.data === 'string' && m.data.length <= 65536
         ? { type: 'stdin', channel: m.channel, data: m.data }
         : null;
+    case 'answer': {
+      if (!isU32(m.channel)) return null;
+      if (m.action === 'select')
+        return isCount(m.optionN) && (m.optionN as number) >= 1 && (m.optionN as number) <= 99
+          ? { type: 'answer', channel: m.channel, action: 'select', optionN: m.optionN as number }
+          : null;
+      return m.action === 'confirm' || m.action === 'deny'
+        ? { type: 'answer', channel: m.channel, action: m.action }
+        : null;
+    }
     case 'resize':
       return isU32(m.channel) && isDim(m.cols) && isDim(m.rows)
         ? { type: 'resize', channel: m.channel, cols: m.cols, rows: m.rows }

packages/shared/test/protocol.test.ts

@@ -42,6 +42,15 @@ function assertInvariants(msg: ClientMessage): void {
       expect(typeof msg.data).toBe('string');
       expect(msg.data.length).toBeLessThanOrEqual(65536);
       break;
+    case 'answer':
+      expect(isU32(msg.channel)).toBe(true);
+      expect(['select', 'confirm', 'deny']).toContain(msg.action);
+      if (msg.action === 'select') {
+        expect(typeof msg.optionN).toBe('number');
+        expect(msg.optionN).toBeGreaterThanOrEqual(1);
+        expect(msg.optionN).toBeLessThanOrEqual(99);
+      }
+      break;
     case 'resize':
       expect(isU32(msg.channel)).toBe(true);
       expect(isDim(msg.cols)).toBe(true);
@@ -92,6 +101,18 @@ describe('parseClientMessage — cas valides', () => {
       .toEqual({ type: 'resize', channel: 3, cols: 120, rows: 32 });
   });
 
+  it('answer select / confirm / deny', () => {
+    expect(parseClientMessage('{"type":"answer","channel":2,"action":"select","optionN":3}'))
+      .toEqual({ type: 'answer', channel: 2, action: 'select', optionN: 3 });
+    expect(parseClientMessage('{"type":"answer","channel":2,"action":"confirm"}'))
+      .toEqual({ type: 'answer', channel: 2, action: 'confirm' });
+    expect(parseClientMessage('{"type":"answer","channel":2,"action":"deny"}'))
+      .toEqual({ type: 'answer', channel: 2, action: 'deny' });
+    // optionN n'est porté que par 'select' (ignoré pour confirm/deny)
+    expect(parseClientMessage('{"type":"answer","channel":2,"action":"deny","optionN":3}'))
+      .toEqual({ type: 'answer', channel: 2, action: 'deny' });
+  });
+
   it('ack à zéro octet', () => {
     expect(parseClientMessage('{"type":"ack","channel":1,"bytes":0}')).toEqual({ type: 'ack', channel: 1, bytes: 0 });
   });
@@ -153,6 +174,15 @@ describe('parseClientMessage — cas malformés', () => {
     expect(parseClientMessage('{"type":"stdin","channel":1}')).toBeNull();
   });
 
+  it('answer : action inconnue, optionN manquant/hors bornes, channel invalide', () => {
+    expect(parseClientMessage('{"type":"answer","channel":1,"action":"select"}')).toBeNull(); // optionN requis
+    expect(parseClientMessage('{"type":"answer","channel":1,"action":"select","optionN":0}')).toBeNull();
+    expect(parseClientMessage('{"type":"answer","channel":1,"action":"select","optionN":100}')).toBeNull();
+    expect(parseClientMessage('{"type":"answer","channel":1,"action":"select","optionN":1.5}')).toBeNull();
+    expect(parseClientMessage('{"type":"answer","channel":1,"action":"nope"}')).toBeNull();
+    expect(parseClientMessage('{"type":"answer","channel":-1,"action":"deny"}')).toBeNull();
+  });
+
   it('ack : bytes négatif ou non numérique', () => {
     expect(parseClientMessage('{"type":"ack","channel":1,"bytes":-1}')).toBeNull();
     expect(parseClientMessage('{"type":"ack","channel":1,"bytes":"0"}')).toBeNull();
@@ -168,16 +198,16 @@ describe('parseClientMessage — cas malformés', () => {
 describe('parseClientMessage — fuzz rapide', () => {
   it('ne lève jamais et tout message accepté respecte les invariants', () => {
     const rand = mulberry32(0xa5b0e7);
-    const types = ['hello', 'attach', 'detach', 'stdin', 'resize', 'ack', 'sub', 'ping', 'unknown', '', 'HELLO', 42, null];
+    const types = ['hello', 'attach', 'detach', 'stdin', 'answer', 'resize', 'ack', 'sub', 'ping', 'unknown', '', 'HELLO', 42, null];
     const values: unknown[] = [
-      undefined, null, true, false, 0, -1, 1, 1.5, 2, 999, 1000, 1001, 0xffffffff, 0x100000000,
-      -0.0001, 1e21, '', 'x', '42', 'interactive', 'observer', 'sessions', {}, [], ['sessions'],
+      undefined, null, true, false, 0, -1, 1, 1.5, 2, 99, 100, 999, 1000, 1001, 0xffffffff, 0x100000000,
+      -0.0001, 1e21, '', 'x', '42', 'interactive', 'observer', 'sessions', 'select', 'confirm', 'deny', {}, [], ['sessions'],
       ['sessions', 'sessions'], ['sessions', 'other'], [42], 'a'.repeat(70000),
     ];
     const pick = <T>(arr: T[]): T => arr[Math.floor(rand() * arr.length)] as T;
     for (let i = 0; i < 1000; i++) {
       const obj: Record<string, unknown> = { type: pick(types) };
-      for (const key of ['protocol', 'sessionId', 'mode', 'cols', 'rows', 'channel', 'data', 'bytes', 'topics']) {
+      for (const key of ['protocol', 'sessionId', 'mode', 'cols', 'rows', 'channel', 'data', 'bytes', 'topics', 'action', 'optionN']) {
         if (rand() < 0.7) obj[key] = pick(values);
       }
       const raw = JSON.stringify(obj);