New subcommands:
- daemon: Listen for IPC lock commands
- lock: Send to daemon or lock directly
- status: Query lock state from daemon
- shutdown: Gracefully stop daemon

Default (no args) locks directly for backwards compatibility.
Daemon handles lock/query-state/shutdown commands via IPC.

Unix socket-based IPC at $XDG_RUNTIME_DIR/garlock.sock:
- JSON protocol with Command/Response/Event types
- Non-blocking server for daemon mode
- Client for sending commands to running daemon
- Socket cleanup on exit

Required for graceful daemon shutdown on SIGTERM/SIGINT.

Document common strftime patterns:
- 24-hour with/without seconds
- 12-hour with AM/PM
- Day and full date formats

Production builds no longer allow escape to exit - only successful
PAM authentication unlocks the screen. Use --features dev for testing.

Significantly faster blur processing by:
1. Downsampling image to 1/4 resolution
2. Applying blur at reduced size (16x fewer pixels)
3. Upsampling back to original resolution

Especially beneficial on ARM where image processing is slower.

- Add overlay renderer initialization
- Composite time, caps lock, failed attempts, and cooldown overlays
- Position overlays relative to ring center
- Add periodic 1-second timer for time display updates
- Make escape key exit conditional on 'dev' feature

Pango/Cairo-based text rendering for:
- Configurable time display with strftime formats
- Caps Lock warning indicator
- Failed authentication attempts counter
- Cooldown timer display

Includes alpha compositing for overlay blending onto background.

Required for configurable time display on lock screen with strftime patterns.

- Block authentication during cooldown period
- Start cooldown after max_attempts failures (default 3)
- Configurable cooldown duration (default 5 seconds)
- Reset attempt counter after cooldown expires

- CLI with clap: --daemon, --config, --debug, --lock
- Screenshot capture and blur on startup
- Keyboard input handling with ring feedback
- PAM authentication on Enter key
- Timer-based state updates and rendering

- Background thread for non-blocking auth
- Password verification via system-auth PAM stack
- Requires /etc/pam.d/garlock config

- AuthState: Idle, Validating, Invalid
- InputState: Idle, Letter, Backspace, Clear, Neutral
- Timer-based state decay (300ms input, 1500ms invalid)
- Ring state mapping from combined auth/input states

- Automatic memory zeroing on drop
- UTF-8 character support for international passwords
- Proper backspace handling for multi-byte characters

- Keycode to character mapping via xkbcommon
- Special key detection: Enter, Backspace, Escape, Ctrl+U
- Modifier key filtering (Shift, Ctrl, Alt, Caps Lock)
- Caps Lock state detection

- Cairo-based circular ring rendering
- State-based colors: idle, typing, verifying, wrong, clear
- Segment highlighting for keystroke feedback
- Alpha compositing onto background

- Convert screenshot to blurred background
- Configurable blur radius and brightness
- Fallback solid color support

- XGetImage-based screen capture
- BGRA pixel format for X11 compatibility

- LockerWindow for fullscreen override-redirect window
- Keyboard and pointer grabs for security
- RandR monitor detection for multi-monitor support

- Config structs for general, background, ring, indicator, font
- Auto-create default config on first run
- Load from ~/.config/garlock/config.toml