feat(tui): single ctrl+c clears input, double ctrl+c exits

docs/plans/state.json

@@ -5438,6 +5438,21 @@
         "docs/plans/state.json"
       ],
       "test_status": "pnpm test:run src/gateway/session-bridge.test.ts src/gateway/server.test.ts src/models/router.test.ts src/models/retry.test.ts + pnpm typecheck passing"
+    },
+    "tui-double-ctrlc-exit-single-ctrlc-clear": {
+      "status": "completed",
+      "date": "2026-02-18",
+      "updated": "2026-02-18",
+      "summary": "Adjusted TUI keyboard behavior to keep /quit while making Ctrl+C safer: in minimal mode first Ctrl+C clears input and second quick Ctrl+C exits; fullscreen mode mirrors double-press Ctrl+C exit semantics while preserving Esc cancellation. Updated docs and regression tests.",
+      "files_modified": [
+        "src/frontends/tui/minimal.ts",
+        "src/frontends/tui/minimal.test.ts",
+        "src/frontends/tui/components/App.tsx",
+        "src/cli/tui.ts",
+        "README.md",
+        "docs/plans/state.json"
+      ],
+      "test_status": "pnpm test:run src/frontends/tui/minimal.test.ts src/frontends/tui/commands.test.ts + pnpm typecheck passing"
     }
   },
   "overall_progress": {