feat(FN-1255): add comment-aware heartbeat wakes and blocked-state dedup

- Add BlockedStateSnapshot typing/export and AgentStore persistence APIs for last blocked heartbeat state
- Deduplicate blocked-task heartbeat comments using blockedBy + context hash, and clear blocked snapshots when tasks are no longer blocked
- Thread triggeringCommentIds/triggeringCommentType through heartbeat execution, wake context, scheduler assignment triggers, and runtime wiring
- Trigger immediate heartbeat runs from task/steering comment routes for assigned immediate-response agents, with validation for comment wake fields on /api/agents/:id/runs
- Expand core, engine, and dashboard tests to cover blocked dedup logic, comment-triggered wakes, validation, and skip scenarios

packages/dashboard/src/server.ts

@@ -92,7 +92,15 @@ export interface ServerOptions {
   /** Optional HeartbeatMonitor for triggering agent execution runs */
   heartbeatMonitor?: {
     startRun(agentId: string, options?: { source: import("@fusion/core").HeartbeatInvocationSource; triggerDetail?: string; contextSnapshot?: Record<string, unknown> }): Promise<import("@fusion/core").AgentHeartbeatRun>;
-    executeHeartbeat(options: { agentId: string; source: import("@fusion/core").HeartbeatInvocationSource; triggerDetail?: string; taskId?: string; contextSnapshot?: Record<string, unknown> }): Promise<import("@fusion/core").AgentHeartbeatRun>;
+    executeHeartbeat(options: {
+      agentId: string;
+      source: import("@fusion/core").HeartbeatInvocationSource;
+      triggerDetail?: string;
+      taskId?: string;
+      triggeringCommentIds?: string[];
+      triggeringCommentType?: "steering" | "task" | "pr";
+      contextSnapshot?: Record<string, unknown>;
+    }): Promise<import("@fusion/core").AgentHeartbeatRun>;
     stopRun(agentId: string): Promise<void>;
   };
 }