feat(terminals): reprise de conversation par cellule + fix ordre d'écriture

Permet de recharger la conversation CLI précédente de chaque cellule à la
réouverture du projet, de façon universelle (indépendant du modèle/CLI).

- profil AgentRuntime: bloc déclaratif optionnel `session { assignFlag, resumeFlag }`
- LeafCell: `conversationId` (persistant, distinct du SessionId PTY) + `agentWasRunning`
- runtime: SessionPlan (None/Assign/Resume) + composition pure des args
- LaunchAgent: décide Assign vs Resume, génère l'UUID, remonte l'id assigné
  (persistance par l'appelant via setCellConversation — découplage SRP)
- close: SnapshotRunningAgents fige `agentWasRunning` avant le kill-all
  (statut clot/en cours universel, sans parsing CLI)
- SessionInspector: port optionnel best-effort + adapter ClaudeTranscriptInspector
- popup de reprise par cellule (statut + sujet/tokens si dispo), intercalée
  avant le Resume auto, jamais sur le chemin reattach

fix(terminals): sérialise les écritures PTY (file FIFO par handle) — corrige
les caractères mélangés/accents dus au réordonnancement des invoke Tauri concurrents

fix(layout): l'opération `move` préservait mal les champs du leaf (perdait `agent`)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/adapters/mock/index.ts

@@ -30,6 +30,7 @@ import type {
 } from "@/domain";
 import type {
   AgentGateway,
+  ConversationDetails,
   CreateAgentInput,
   CreateSkillInput,
   CreateTemplateInput,
@@ -323,7 +324,17 @@ export class MockAgentGateway implements AgentGateway {
     queueMicrotask(() =>
       session.emit(enc.encode(`agent ${agentId} @ ${cwd}\r\n`)),
     );
-    return makeMockHandle(session, () => this.sessions.delete(sessionId));
+    const handle = makeMockHandle(session, () => this.sessions.delete(sessionId));
+    // Simulate session assignment (T4b): a fresh cell (no conversation id) gets a
+    // newly-minted id surfaced on the handle so the caller persists it; a cell
+    // that already carries an id resumes it and nothing new is assigned.
+    if (!options.conversationId) {
+      return {
+        ...handle,
+        assignedConversationId: `mock-conversation-${sessionId}`,
+      };
+    }
+    return handle;
   }
 
   async reattach(
@@ -344,6 +355,31 @@ export class MockAgentGateway implements AgentGateway {
       scrollback,
     };
   }
+
+  /**
+   * Best-effort conversation details, keyed by conversation id (T7). Empty by
+   * default (degraded mode); a test seeds enriched details via
+   * {@link _setConversationDetails}.
+   */
+  private conversationDetails = new Map<string, ConversationDetails>();
+
+  /** Seeds the (best-effort) details returned for a given conversation id. */
+  _setConversationDetails(
+    conversationId: string,
+    details: ConversationDetails,
+  ): void {
+    this.conversationDetails.set(conversationId, details);
+  }
+
+  async inspectConversation(
+    _projectId: string,
+    _agentId: string,
+    conversationId: string,
+  ): Promise<ConversationDetails> {
+    // Best-effort: an unknown conversation yields empty details (degraded mode),
+    // never an error — mirroring the backend contract.
+    return structuredClone(this.conversationDetails.get(conversationId) ?? {});
+  }
 }
 
 /**
@@ -421,6 +457,16 @@ export class MockTerminalGateway implements TerminalGateway {
       scrollback,
     };
   }
+
+  async closeTerminal(sessionId: string): Promise<void> {
+    // Best-effort / idempotent: kill the PTY by id (mirrors the handle's close)
+    // so a later reattach to it fails. No-op if the session is already gone.
+    const session = this.sessions.get(sessionId);
+    if (session) {
+      session.closed = true;
+      this.sessions.delete(sessionId);
+    }
+  }
 }
 
 export class MockProjectGateway implements ProjectGateway {