Initial commit: Screen Leads app

Screen-capture lead tool: capture agent, Claude vision extractor with
pluggable site recipes (LinkedIn), canonical funnel model, SQLite storage,
FastAPI backend, dashboard, and setup/run scripts.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

agent/screenshot.py

@@ -0,0 +1,35 @@
+"""Cross-platform full-screen capture via `mss` (Windows, macOS, Linux/X11)."""
+from __future__ import annotations
+
+import time
+from pathlib import Path
+from typing import Optional
+
+from config import SCREENSHOT_DIR
+
+
+class CaptureError(RuntimeError):
+    pass
+
+
+def capture(prefix: str = "shot") -> str:
+    """Grab the primary monitor to a PNG and return its path."""
+    try:
+        import mss
+        import mss.tools
+    except Exception as e:  # pragma: no cover
+        raise CaptureError(f"mss not available: {e}")
+
+    ts = int(time.time() * 1000)
+    path = SCREENSHOT_DIR / f"{prefix}_{ts}.png"
+    try:
+        with mss.mss() as sct:
+            monitor = sct.monitors[1]  # [0] is the virtual "all monitors" rect
+            img = sct.grab(monitor)
+            mss.tools.to_png(img.rgb, img.size, output=str(path))
+    except Exception as e:
+        raise CaptureError(
+            f"Screen capture failed ({e}). On macOS grant Screen Recording; "
+            f"on Linux use an X11 session (Wayland needs the screenshot portal)."
+        )
+    return str(path)