feat(session-limits): LS7-front — UI limites de session (badge + compte à rebours + filet humain)

Expose la surface produit des limites de session côté React/TS,
au-dessus du câblage backend (9df5923).

- domain/index.ts : 5 variantes ajoutées au union DomainEvent
  (agentRateLimited / ResumeScheduled / ResumeCancelled / Resumed /
  RateLimitSuspected).
- ports/index.ts : cancelResume(agentId) ajouté à InputGateway.
- adapters/input.ts : TauriInputGateway.cancelResume → invoke("cancel_resume").
- adapters/mock/index.ts : MockInputGateway.cancelResume
  (cancelledResumes / cancelResumeResult).
- features/agents/useAgents.ts : état limitByAgent + action cancelResume.
- features/agents/AgentLimitBadge.tsx (nouveau) : badge + compte à rebours
  + bouton Annuler + helpers purs.
- features/agents/AgentsPanel.tsx : câblage du badge.

Tests : useAgentsLimits.test.tsx (13) + AgentLimitBadge.test.tsx (11),
suite agents 63 tests verts, tsc --noEmit propre.

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

frontend/src/domain/index.ts

@@ -36,6 +36,55 @@ export type DomainEvent =
       submitSequence?: string;
       submitDelayMs?: number;
     }
+  | {
+      /**
+       * An agent entered a session/rate limit (ARCHITECTURE §21). Low-frequency,
+       * model-agnostic. `resetsAtMs` is the reset instant in epoch-milliseconds;
+       * absent ⇒ unknown (no reliable time → no auto-resume). The frontend badges
+       * "limité jusqu'à HH:MM" when known, "limité" otherwise.
+       */
+      type: "agentRateLimited";
+      agentId: string;
+      resetsAtMs?: number;
+    }
+  | {
+      /**
+       * An auto-resume was armed for a rate-limited agent (ARCHITECTURE §21).
+       * `fireAtMs` is the wake-up deadline in epoch-milliseconds. The frontend
+       * shows the countdown + the "Annuler la reprise" button (cancellable window).
+       */
+      type: "agentResumeScheduled";
+      agentId: string;
+      fireAtMs: number;
+    }
+  | {
+      /**
+       * An agent's auto-resume was cancelled (ARCHITECTURE §21): the user clicked
+       * "Annuler la reprise". The frontend removes the countdown but keeps the
+       * "limité" state (no auto-resume will fire).
+       */
+      type: "agentResumeCancelled";
+      agentId: string;
+    }
+  | {
+      /**
+       * An agent was effectively resumed after a limit (ARCHITECTURE §21): the
+       * wake-up fired (or an immediate resume). The frontend clears all limit state.
+       */
+      type: "agentResumed";
+      agentId: string;
+    }
+  | {
+      /**
+       * Human net (level 3): a session limit is suspected without any reliable
+       * reset time (ARCHITECTURE §21.1). IdeA never resumes blind: this asks the
+       * frontend to surface an "heure inconnue" state and prompt the user.
+       * `resetsAtMs` carries an estimate when one exists, else absent.
+       */
+      type: "agentRateLimitSuspected";
+      agentId: string;
+      resetsAtMs?: number;
+    }
   | { type: "templateUpdated"; templateId: string; version: number }
   | { type: "agentDriftDetected"; agentId: string; from: number; to: number }
   | { type: "agentSynced"; agentId: string; to: number }