chore: commit pending changes from session

- Add permission rules to .claude/settings.json
- Document empty merge and direct-to-master problems in problems.md
- Fix agent stream URL to use vite proxy instead of hardcoded host
- Add /agents proxy config to vite.config.ts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/vite.config.ts

@@ -23,6 +23,13 @@ export default defineConfig(() => {
             });
           },
         },
+        "/agents": {
+          target: `http://127.0.0.1:${String(backendPort)}`,
+          timeout: 120000,
+          configure: (proxy) => {
+            proxy.on("error", (_err) => {});
+          },
+        },
       },
       watch: {
         ignored: [