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.

requirements-pi.txt

@@ -0,0 +1,8 @@
+# Additional dependencies needed only on the real Raspberry Pi, for the
+# epdconfig.py driver to talk to the panel over SPI/GPIO. Not needed for
+# local development with --mock (and RPi.GPIO/lgpio generally won't even
+# build off a Pi), so these are kept out of requirements.txt.
+gpiozero==2.0.1
+lgpio==0.2.2.0
+RPi.GPIO==0.7.1
+spidev>=3.6