feat(glitch-detector): add --live browser vision integration for live world scanning

- Add --live flag to use Playwright-based browser capture
- Implement _browser_capture() with Playwright for live scanning
- Support camera angle rotation (yaw/pitch) for multi-angle sweep
- Fall back to placeholder when --live not set and Playwright unavailable
- Hard-fail fast when --live is set but Playwright not installed

Closes #541

bin/matrix_glitch_detector.py

@@ -37,6 +37,12 @@ from glitch_patterns import (
 )
 
 
+
+try:
+    from playwright.sync_api import sync_playwright
+    _PLAYWRIGHT_AVAILABLE = True
+except ImportError:
+    _PLAYWRIGHT_AVAILABLE = False
 @dataclass
 class DetectedGlitch:
     """A single detected glitch with metadata."""
@@ -97,7 +103,7 @@ def generate_scan_angles(num_angles: int) -> list[dict]:
     ]
 
 
-def capture_screenshots(url: str, angles: list[dict], output_dir: Path) -> list[Path]:
+def capture_screenshots(url: str, angles: list[dict], output_dir: Path, live: bool = False) -> list[Path]:
     """Capture screenshots of a 3D web world from multiple angles.
 
     Uses browser_vision tool when available; falls back to placeholder generation
@@ -111,7 +117,7 @@ def capture_screenshots(url: str, angles: list[dict], output_dir: Path) -> list[
 
         # Attempt browser-based capture via browser_vision
         try:
-            result = _browser_capture(url, angle, filename)
+            result = _browser_capture(url, angle, filename, live=live)
             if result:
                 screenshots.append(filename)
                 continue
@@ -125,26 +131,83 @@ def capture_screenshots(url: str, angles: list[dict], output_dir: Path) -> list[
     return screenshots
 
 
-def _browser_capture(url: str, angle: dict, output_path: Path) -> bool:
+def _browser_capture(url: str, angle: dict, output_path: Path, live: bool = False) -> bool:
     """Capture a screenshot via browser automation.
     
-    This is a stub that delegates to the browser_vision tool when run
-    in an environment that provides it. In CI or offline mode, returns False.
+    Uses Playwright to navigate to the URL and capture a screenshot.
+    In live mode, this is required; otherwise, falls back to placeholder.
+    
+    Args:
+        url: Target URL to scan
+        angle: Camera angle dict with yaw/pitch/label
+        output_path: Where to save the screenshot
+        live: If True, hard-fail when browser unavailable
+    
+    Returns:
+        True on success, False otherwise
     """
-    # Check if browser_vision is available via environment
-    bv_script = os.environ.get("BROWSER_VISION_SCRIPT")
-    if bv_script and Path(bv_script).exists():
-        import subprocess
-        cmd = [
-            sys.executable, bv_script,
-            "--url", url,
-            "--screenshot", str(output_path),
-            "--rotate-yaw", str(angle["yaw"]),
-            "--rotate-pitch", str(angle["pitch"]),
-        ]
-        proc = subprocess.run(cmd, capture_output=True, text=True, timeout=30)
-        return proc.returncode == 0 and output_path.exists()
-    return False
+    # Import check
+    if not _PLAYWRIGHT_AVAILABLE:
+        if live:
+            raise ImportError(
+                "browser automation requires playwright. Install with: pip install playwright && playwright install chromium"
+            )
+        return False
+
+    try:
+        with sync_playwright() as p:
+            browser = p.chromium.launch(headless=True)
+            page = browser.new_page(viewport={"width": 1280, "height": 720})
+            page.goto(url, wait_until="networkidle", timeout=30000)
+            page.wait_for_timeout(2000)
+
+            # Rotate camera if using custom angles (yaw/pitch in degrees)
+            yaw = angle.get("yaw", 0)
+            pitch = angle.get("pitch", 0)
+            if yaw != 0 or pitch != 0:
+                yaw_rad = yaw * (3.14159 / 180)
+                pitch_rad = pitch * (3.14159 / 180)
+                js = f"""
+                (function() {{
+                    // Try common Three.js camera locations
+                    let cam = null;
+                    if (window.renderer && window.renderer.camera) cam = window.renderer.camera;
+                    else if (window.scene && window.scene.camera) cam = window.scene.camera;
+                    else if (window.camera) cam = window.camera;
+                    // Check for Three.js r125+ camera in renderer.info
+                    const canvases = document.querySelectorAll('canvas');
+                    for (const c of canvases) {{
+                        if (c.__three__ && c.__three__.camera) {{ cam = c.__three__.camera; break; }}
+                    }}
+                    if (cam) {{
+                        cam.rotation.set({pitch_rad}, {yaw_rad}, 0, 'YXZ');
+                        if (cam.updateMatrixWorld) cam.updateMatrixWorld();
+                    }}
+                }})();
+                """
+                page.evaluate(js)
+                page.wait_for_timeout(500)
+
+            page.screenshot(path=str(output_path))
+            browser.close()
+            return output_path.exists()
+    except Exception as e:
+        if live:
+            raise
+        # Silent fail for automatic fallback
+        return False
+
+
+def _generate_placeholder_screenshot(path: Path, angle: dict):
+    """Generate a minimal 1x1 PNG as a placeholder for testing."""
+    png_data = (
+        b"\x89PNG\r\n\x1a\n"
+        b"\x00\x00\x00\rIHDR\x00\x00\x00\x01\x00\x00\x00\x01"
+        b"\x08\x06\x00\x00\x00\x1f\x15\xc4\x89"
+        b"\x00\x00\x00\nIDATx\x9cc\x00\x01\x00\x00\x05\x00\x01"
+        b"\r\n\xb4\x00\x00\x00\x00IEND\xaeB`\x82"
+    )
+    path.write_bytes(png_data)
 
 
 def _generate_placeholder_screenshot(path: Path, angle: dict):
@@ -524,6 +587,11 @@ Examples:
         help="Minimum severity to include in report",
     )
     parser.add_argument("--verbose", "-v", action="store_true", help="Verbose output")
+    parser.add_argument(
+        "--live",
+        action="store_true",
+        help="Use live browser automation (requires playwright); falls back to placeholders if unavailable",
+    )
     parser.add_argument(
         "--threejs",
         action="store_true",
@@ -555,7 +623,7 @@ Examples:
 
     # Capture screenshots
     screenshots_dir = Path(f"/tmp/matrix_glitch_{scan_id}")
-    screenshots = capture_screenshots(args.url, angles, screenshots_dir)
+    screenshots = capture_screenshots(args.url, angles, screenshots_dir, live=args.live)
     print(f"[*] Captured {len(screenshots)} screenshots")
 
     # Filter patterns by severity and type