Initial commit: Paperwall, a standalone e-ink dashboard

Navidrome now-playing, clock, and weather for a Waveshare epd4in0e panel,
with a local web UI and install/uninstall scripts for the Pi.

display/mock_driver.py

@@ -0,0 +1,35 @@
+"""Development stand-in for the real panel: saves each frame as a PNG instead
+of writing to hardware, so the scheduler/rendering logic can be exercised off
+the Pi.
+"""
+
+import logging
+from pathlib import Path
+
+from PIL import Image
+
+from display import Display
+
+logger = logging.getLogger(__name__)
+
+
+class MockDisplay(Display):
+    def __init__(self, resolution: tuple[int, int], out_dir: str = "./mock_output"):
+        self.resolution = resolution
+        self.out_dir = Path(out_dir)
+        self.out_dir.mkdir(parents=True, exist_ok=True)
+        self._frame_count = 0
+
+    def init(self) -> None:
+        logger.info("MockDisplay initialized (resolution=%s)", self.resolution)
+
+    def show(self, image: Image.Image) -> None:
+        self._frame_count += 1
+        path = self.out_dir / "current.png"
+        image.save(path)
+        history_path = self.out_dir / f"frame_{self._frame_count:04d}.png"
+        image.save(history_path)
+        logger.info("MockDisplay: wrote frame to %s", path)
+
+    def sleep(self) -> None:
+        logger.info("MockDisplay: sleep")