docs: Update agent documentation

Updated agent.md documentation.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/trpc/routers/architect.ts

@@ -82,6 +82,33 @@ export function architectProcedures(publicProcedure: ProcedureBuilder) {
           });
         }
 
+        // Auto-dismiss stale breakdown agents
+        const allAgents = await agentManager.list();
+        const staleAgents = allAgents.filter(
+          (a) =>
+            a.mode === 'breakdown' &&
+            a.initiativeId === input.initiativeId &&
+            ['crashed', 'idle'].includes(a.status) &&
+            !a.userDismissedAt,
+        );
+        for (const stale of staleAgents) {
+          await agentManager.dismiss(stale.id);
+        }
+
+        // Reject if a breakdown agent is already active for this initiative
+        const activeBreakdownAgents = allAgents.filter(
+          (a) =>
+            a.mode === 'breakdown' &&
+            a.initiativeId === input.initiativeId &&
+            ['running', 'waiting_for_input'].includes(a.status),
+        );
+        if (activeBreakdownAgents.length > 0) {
+          throw new TRPCError({
+            code: 'CONFLICT',
+            message: 'A breakdown agent is already running for this initiative',
+          });
+        }
+
         const task = await taskRepo.create({
           initiativeId: input.initiativeId,
           name: `Breakdown: ${initiative.name}`,