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

AGENTS.md

@@ -25,12 +25,22 @@ uv sync
 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
 
 **At the start of every agent session**, verify hooks are installed:
@@ -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

engine/app.py

@@ -33,13 +33,25 @@ from engine.websocket_display import WebSocketDisplay
 
 
 def _get_display():
-    """Get the appropriate display based on config."""
-    if config.WEBSOCKET:
+    """Get the appropriate display(s) based on config."""
+    from engine.display import MultiDisplay, TerminalDisplay
+
+    displays = []
+
+    if config.DISPLAY in ("terminal", "both"):
+        displays.append(TerminalDisplay())
+
+    if config.DISPLAY in ("websocket", "both") or config.WEBSOCKET:
         ws = WebSocketDisplay(host="0.0.0.0", port=config.WEBSOCKET_PORT)
         ws.start_server()
         ws.start_http_server()
-        return ws
+        displays.append(ws)
+
+    if not displays:
         return None
+    if len(displays) == 1:
+        return displays[0]
+    return MultiDisplay(displays)
 
 
 TITLE = [

engine/config.py

@@ -127,6 +127,7 @@ class Config:
 
     script_fonts: dict[str, str] = field(default_factory=_get_platform_font_paths)
 
+    display: str = "terminal"
     websocket: bool = False
     websocket_port: int = 8765
 
@@ -167,6 +168,7 @@ class Config:
             glitch_glyphs="░▒▓█▌▐╌╍╎╏┃┆┇┊┋",
             kata_glyphs="ﾊﾐﾋｰｳｼﾅﾓﾆｻﾜﾂｵﾘｱﾎﾃﾏｹﾒｴｶｷﾑﾕﾗｾﾈｽﾀﾇﾍ",
             script_fonts=_get_platform_font_paths(),
+            display=_arg_value("--display", argv) or "terminal",
             websocket="--websocket" in argv,
             websocket_port=_arg_int("--websocket-port", 8765, argv),
         )
@@ -229,6 +231,7 @@ GLITCH = "░▒▓█▌▐╌╍╎╏┃┆┇┊┋"
 KATA = "ﾊﾐﾋｰｳｼﾅﾓﾆｻﾜﾂｵﾘｱﾎﾃﾏｹﾒｴｶｷﾑﾕﾗｾﾈｽﾀﾇﾍ"
 
 # ─── WEBSOCKET ─────────────────────────────────────────────
+DISPLAY = _arg_value("--display", sys.argv) or "terminal"
 WEBSOCKET = "--websocket" in sys.argv
 WEBSOCKET_PORT = _arg_int("--websocket-port", 8765)
 

engine/display.py

@@ -100,3 +100,30 @@ class NullDisplay:
 
     def cleanup(self) -> None:
         pass
+
+
+class MultiDisplay:
+    """Display that forwards to multiple displays."""
+
+    def __init__(self, displays: list[Display]):
+        self.displays = displays
+        self.width = 80
+        self.height = 24
+
+    def init(self, width: int, height: int) -> None:
+        self.width = width
+        self.height = height
+        for d in self.displays:
+            d.init(width, height)
+
+    def show(self, buffer: list[str]) -> None:
+        for d in self.displays:
+            d.show(buffer)
+
+    def clear(self) -> None:
+        for d in self.displays:
+            d.clear()
+
+    def cleanup(self) -> None:
+        for d in self.displays:
+            d.cleanup()

engine/websocket_display.py

@@ -193,11 +193,9 @@ class WebSocketDisplay:
     def _run_async(self, coro):
         """Run coroutine in background."""
         try:
-            loop = asyncio.new_event_loop()
-            asyncio.set_event_loop(loop)
-            loop.run_until_complete(coro)
-        except Exception:
-            pass
+            asyncio.run(coro)
+        except Exception as e:
+            print(f"WebSocket async error: {e}")
 
     def start_server(self):
         """Start the WebSocket server in a background thread."""
@@ -224,6 +222,8 @@ class WebSocketDisplay:
         if self._http_thread is not None:
             return
 
+        self._http_running = True
+
         self._http_running = True
         self._http_thread = threading.Thread(
             target=self._run_async, args=(self._run_http_server(),), daemon=True

mise.toml

@@ -28,7 +28,8 @@ run = "uv run mainline.py"
 run-poetry = "uv run mainline.py --poetry"
 run-firehose = "uv run mainline.py --firehose"
 run-websocket = { run = "uv run mainline.py --websocket", depends = ["sync-all"] }
-run-client = { run = "uv run mainline.py --websocket & WEBSOCKET_PID=$! && sleep 2 && case $(uname -s) in Darwin) open http://localhost:8766 ;; Linux) xdg-open http://localhost:8766 ;; CYGWIN*) cmd /c start http://localhost:8766 ;; *) echo 'Unknown platform' ;; esac && wait $WEBSOCKET_PID", depends = ["sync-all"] }
+run-both = { run = "uv run mainline.py --display both", depends = ["sync-all"] }
+run-client = { run = "uv run mainline.py --display both & WEBSOCKET_PID=$! && sleep 2 && case $(uname -s) in Darwin) open http://localhost:8766 ;; Linux) xdg-open http://localhost:8766 ;; CYGWIN*) cmd /c start http://localhost:8766 ;; *) echo 'Unknown platform' ;; esac && wait $WEBSOCKET_PID", depends = ["sync-all"] }
 
 # =====================
 # Environment