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/ports/index.ts

@@ -552,6 +552,15 @@ export interface InputGateway {
    * mounted cell keeps the write-portal path. Best-effort; never throws into the UI.
    */
   setFrontAttached(agentId: string, attached: boolean): Promise<void>;
+  /**
+   * Cancels the **auto-resume** armed for a rate-limited agent (ARCHITECTURE §21):
+   * the user clicked "Annuler la reprise" during the cancellable window. Disarms
+   * the scheduled wake-up. Resolves to `true` iff a resume was effectively
+   * cancelled (a wake-up was still pending); `false` if none was armed or it had
+   * already fired (the resume then runs its course). The backend also emits
+   * `agentResumeCancelled` on success, which clears the countdown in the UI.
+   */
+  cancelResume(agentId: string): Promise<boolean>;
 }
 
 /**