feat: switch to uv, add check command, fix silent a11y failures

- Added pyobjc-framework-ApplicationServices to dependencies (was
  implicitly available via pyenv's system packages but missing in
  clean venvs)
- Added `cursor-flasher check` command that verifies Cursor is running
  and accessibility permissions are working
- Detector now logs a warning when a11y tree reads fail (previously
  failed silently, making permission issues invisible)
- Switched to uv for dependency management: `uv sync` + `uv run`
- Updated README with uv-based workflow and accessibility
  troubleshooting guide

Made-with: Cursor

chat-summaries/2026-03-10_02-57-summary.md

@@ -0,0 +1,40 @@
+# cursor-flasher: Full Implementation
+
+**Date:** 2026-03-10
+**Branch:** feat/cursor-flasher → merged to master (14 commits)
+
+## Task
+
+Build a macOS daemon that monitors Cursor IDE's accessibility tree and shows a pulsing border overlay + plays a sound when the AI agent is waiting for user input.
+
+## Changes Made
+
+### Core Modules (src/cursor_flasher/)
+- **config.py** — Dataclass-based config with YAML loading from `~/.cursor-flasher/config.yaml`
+- **state.py** — State machine: IDLE → AGENT_WORKING → WAITING_FOR_USER with cooldown logic
+- **detector.py** — Per-window accessibility tree scanning; detects approval prompts (Accept, Reject, Run, etc.) and agent-working indicators (Stop, Cancel) via AXStaticText values and AXButton titles
+- **overlay.py** — Native macOS overlay using NSWindow + PulseBorderView with sine-wave opacity animation; reads position directly from AXWindow elements
+- **sound.py** — System sound playback via NSSound
+- **daemon.py** — Main loop wiring detection → state machine → overlay + sound; NSRunLoop-based event loop
+- **cli.py** — `cursor-flasher start/stop/status` CLI with PID file management and fork-based daemonization
+
+### Dev Tools (scripts/)
+- **dump_a11y_tree.py** — Dumps Cursor's full accessibility tree for debugging detection patterns
+- **test_overlay.py** — Manual overlay test with `--per-window` flag
+
+### Tests (31 passing)
+- test_config.py (7), test_state.py (10), test_detector.py (12), test_sound.py (2)
+
+## Key Decisions & Discoveries
+- Cursor's bundle ID is `com.todesktop.230313mzl4w4u92` (not matchable by app name alone)
+- Electron web content exposes UI as AXStaticText values, not AXButton titles
+- CGWindowList returns empty names for Electron windows; position tracking uses AXWindow AXPosition/AXSize via AXValueGetValue instead
+- Per-window detection: only the specific window(s) with active approval prompts get flashed
+- pyproject.toml build-backend corrected from plan's `setuptools.backends._legacy:_Backend` to `setuptools.build_meta`
+- NSRect.insetBy doesn't exist in pyobjc; used NSInsetRect instead
+
+## Follow-up Items
+- Detection patterns may need tuning as Cursor UI evolves
+- No menu bar icon (out of MVP scope)
+- No auto-start on login
+- No multi-monitor awareness beyond what CGWindow/AXWindow coordinates provide