feat(gastown): add POST /debug/reconcile-dry-run endpoint

cloudflare-gastown/src/dos/Town.do.ts

@@ -30,7 +30,7 @@ import * as scheduling from './town/scheduling';
 import * as events from './town/events';
 import * as reconciler from './town/reconciler';
 import { applyAction } from './town/actions';
-import type { ApplyActionContext } from './town/actions';
+import type { Action, ApplyActionContext } from './town/actions';
 import { buildRefinerySystemPrompt } from '../prompts/refinery-system.prompt';
 import { GitHubPRStatusSchema, GitLabMRStatusSchema } from '../util/platform-pr.util';
 
@@ -3684,6 +3684,31 @@ export class TownDO extends DurableObject<Env> {
     };
   }
 
+  // DEBUG: dry-run the reconciler against current state, returning actions
+  // it would emit without applying them. Side-effect-free — reconcile()
+  // only reads SQLite state; applyAction() is never called.
+  async debugDryRun(): Promise<{
+    actions: Action[];
+    metrics: Pick<
+      reconciler.ReconcilerMetrics,
+      'actionsEmitted' | 'actionsByType' | 'pendingEventCount'
+    >;
+  }> {
+    const actions = reconciler.reconcile(this.sql);
+    const actionsByType: Record<string, number> = {};
+    for (const a of actions) {
+      actionsByType[a.type] = (actionsByType[a.type] ?? 0) + 1;
+    }
+    return {
+      actions,
+      metrics: {
+        actionsEmitted: actions.length,
+        actionsByType,
+        pendingEventCount: events.pendingEventCount(this.sql),
+      },
+    };
+  }
+
   // DEBUG: concise non-terminal bead summary — remove after debugging
   async debugBeadSummary(): Promise<unknown[]> {
     return [

cloudflare-gastown/src/gastown.worker.ts

@@ -206,6 +206,14 @@ app.get('/debug/towns/:townId/status', async c => {
   return c.json({ alarmStatus, agentMeta, beadSummary });
 });
 
+app.post('/debug/towns/:townId/reconcile-dry-run', async c => {
+  const townId = c.req.param('townId');
+  const town = getTownDOStub(c.env, townId);
+  // eslint-disable-next-line @typescript-eslint/await-thenable -- DO RPC returns promise at runtime
+  const result = await town.debugDryRun();
+  return c.json(result);
+});
+
 // ── Town ID + Auth ──────────────────────────────────────────────────────
 // All rig routes live under /api/towns/:townId/rigs/:rigId so the townId
 // is always available from the URL path.