feat(display): add configurable multi-backend display system

AGENTS.md

@@ -22,13 +22,23 @@ uv sync
 ### Available Commands
 
 ```bash
-mise run test       # Run tests
-mise run test-v     # Run tests verbose
-mise run test-cov   # Run tests with coverage report
-mise run lint       # Run ruff linter
-mise run lint-fix   # Run ruff with auto-fix
-mise run format     # Run ruff formatter
-mise run ci         # Full CI pipeline (sync + test + coverage)
+mise run test           # Run tests
+mise run test-v         # Run tests verbose
+mise run test-cov       # Run tests with coverage report
+mise run test-browser   # Run e2e browser tests (requires playwright)
+mise run lint           # Run ruff linter
+mise run lint-fix       # Run ruff with auto-fix
+mise run format         # Run ruff formatter
+mise run ci             # Full CI pipeline (sync + test + coverage)
+```
+
+### Runtime Commands
+
+```bash
+mise run run            # Run mainline (terminal)
+mise run run-websocket  # Run with WebSocket display
+mise run run-both       # Run with both terminal and WebSocket
+mise run run-client     # Run both + open browser
 ```
 
 ## Git Hooks
@@ -108,3 +118,11 @@ The project uses pytest with strict marker enforcement. Test configuration is in
 - **eventbus.py** provides thread-safe event publishing for decoupled communication
 - **controller.py** coordinates ntfy/mic monitoring
 - The render pipeline: fetch → render → effects → scroll → terminal output
+- **Display abstraction** (`engine/display.py`): swap display backends via the Display protocol
+  - `TerminalDisplay` - ANSI terminal output
+  - `WebSocketDisplay` - broadcasts to web clients via WebSocket
+  - `MultiDisplay` - forwards to multiple displays simultaneously
+- **WebSocket display** (`engine/websocket_display.py`): real-time frame broadcasting to web browsers
+  - WebSocket server on port 8765
+  - HTTP server on port 8766 (serves HTML client)
+  - Client at `client/index.html` with ANSI color parsing and fullscreen support