feat: Add retry mechanism for blocked tasks

Blocked tasks (from spawn failures) were a dead-end with no way to
recover. Add retryBlockedTask to DispatchManager that resets status
to pending and re-queues, a tRPC mutation that also kicks dispatchNext,
and a Retry button in the task slide-over when status is blocked.

apps/server/dispatch/manager.ts

@@ -237,6 +237,27 @@ export class DefaultDispatchManager implements DispatchManager {
     this.eventBus.emit(event);
   }
 
+  /**
+   * Retry a blocked task.
+   * Resets status to pending, clears block state, and re-queues for dispatch.
+   */
+  async retryBlockedTask(taskId: string): Promise<void> {
+    const task = await this.taskRepository.findById(taskId);
+    if (!task) throw new Error(`Task not found: ${taskId}`);
+    if (task.status !== 'blocked') throw new Error(`Task ${taskId} is not blocked (status: ${task.status})`);
+
+    // Clear blocked state
+    this.blockedTasks.delete(taskId);
+
+    // Reset DB status to pending
+    await this.taskRepository.update(taskId, { status: 'pending' });
+
+    log.info({ taskId }, 'retrying blocked task');
+
+    // Re-queue for dispatch
+    await this.queue(taskId);
+  }
+
   /**
    * Dispatch next available task to an agent.
    */

apps/server/dispatch/phase-manager.test.ts

@@ -50,6 +50,7 @@ function createMockDispatchManager(): DispatchManager {
     dispatchNext: vi.fn().mockResolvedValue({ success: false, reason: 'mock' }),
     completeTask: vi.fn(),
     blockTask: vi.fn(),
+    retryBlockedTask: vi.fn(),
     getQueueState: vi.fn().mockResolvedValue({ queued: [], ready: [], blocked: [] }),
   };
 }

apps/server/dispatch/types.ts

@@ -102,6 +102,14 @@ export interface DispatchManager {
    */
   blockTask(taskId: string, reason: string): Promise<void>;
 
+  /**
+   * Retry a blocked task.
+   * Resets status to pending, removes from blocked map, and re-queues for dispatch.
+   *
+   * @param taskId - ID of the blocked task to retry
+   */
+  retryBlockedTask(taskId: string): Promise<void>;
+
   /**
    * Get current queue state.
    * Returns all queued tasks with their dispatch readiness.

apps/server/trpc/routers/dispatch.ts

@@ -35,5 +35,15 @@ export function dispatchProcedures(publicProcedure: ProcedureBuilder) {
         await dispatchManager.completeTask(input.taskId);
         return { success: true };
       }),
+
+    retryBlockedTask: publicProcedure
+      .input(z.object({ taskId: z.string().min(1) }))
+      .mutation(async ({ ctx, input }) => {
+        const dispatchManager = requireDispatchManager(ctx);
+        await dispatchManager.retryBlockedTask(input.taskId);
+        // Kick dispatch loop to pick up the re-queued task
+        await dispatchManager.dispatchNext();
+        return { success: true };
+      }),
   };
 }

apps/web/src/components/execution/TaskSlideOver.tsx

@@ -1,6 +1,6 @@
 import { useCallback, useEffect, useRef, useMemo } from "react";
 import { motion, AnimatePresence } from "motion/react";
-import { X, Trash2, MessageCircle } from "lucide-react";
+import { X, Trash2, MessageCircle, RotateCw } from "lucide-react";
 import type { ChatTarget } from "@/components/chat/ChatSlideOver";
 import { Badge } from "@/components/ui/badge";
 import { Button } from "@/components/ui/button";
@@ -20,6 +20,7 @@ interface TaskSlideOverProps {
 export function TaskSlideOver({ onOpenChat }: TaskSlideOverProps) {
   const { selectedEntry, setSelectedTaskId } = useExecutionContext();
   const queueTaskMutation = trpc.queueTask.useMutation();
+  const retryBlockedTaskMutation = trpc.retryBlockedTask.useMutation();
   const deleteTaskMutation = trpc.deleteTask.useMutation();
   const updateTaskMutation = trpc.updateTask.useMutation();
 
@@ -229,17 +230,32 @@ export function TaskSlideOver({ onOpenChat }: TaskSlideOverProps) {
 
             {/* Footer */}
             <div className="flex items-center gap-2 border-t border-border px-5 py-3">
-              <Button
-                variant="outline"
-                size="sm"
-                disabled={!canQueue}
-                onClick={() => {
-                  queueTaskMutation.mutate({ taskId: task.id });
-                  close();
-                }}
-              >
-                Queue Task
-              </Button>
+              {task.status === "blocked" ? (
+                <Button
+                  variant="outline"
+                  size="sm"
+                  className="gap-1.5"
+                  onClick={() => {
+                    retryBlockedTaskMutation.mutate({ taskId: task.id });
+                    close();
+                  }}
+                >
+                  <RotateCw className="h-3.5 w-3.5" />
+                  Retry
+                </Button>
+              ) : (
+                <Button
+                  variant="outline"
+                  size="sm"
+                  disabled={!canQueue}
+                  onClick={() => {
+                    queueTaskMutation.mutate({ taskId: task.id });
+                    close();
+                  }}
+                >
+                  Queue Task
+                </Button>
+              )}
               <Button
                 variant="outline"
                 size="sm"

docs/dispatch-events.md

@@ -68,6 +68,7 @@ InitiativeReviewApprovedEvent  { initiativeId, branch, strategy: 'push_branch' |
 6. **Planning skip** — Planning-category tasks (research, discuss, plan, detail, refine) skip auto-dispatch — they use the architect flow
 7. **Summary propagation** — `completeTask()` reads the completing agent's `result.message` and stores it on the task's `summary` column. Dependent tasks see this summary in `context/tasks/<id>.md` frontmatter.
 8. **Spawn failure** — If `agentManager.spawn()` throws, the task is blocked via `blockTask()` with the error message. The dispatch cycle continues instead of crashing.
+9. **Retry blocked** — `retryBlockedTask(taskId)` resets a blocked task to pending and re-queues it. Exposed via tRPC `retryBlockedTask` mutation. The UI shows a Retry button in the task slide-over when status is `blocked`.
 
 ### DispatchManager Methods
 
@@ -78,6 +79,7 @@ InitiativeReviewApprovedEvent  { initiativeId, branch, strategy: 'push_branch' |
 | `getNextDispatchable()` | Get next task without dispatching |
 | `completeTask(taskId, agentId?)` | Complete task |
 | `blockTask(taskId, reason)` | Block task with reason |
+| `retryBlockedTask(taskId)` | Reset blocked task to pending and re-queue |
 | `getQueueState()` | Return queued, ready, blocked tasks |
 
 ## Phase Dispatch