Microscope camera kiosk

Touchscreen kiosk for the Raspberry Pi HQ camera (IMX477) used as a
microscope: live preview from boot, raw frame recording, full-resolution
stills, and automatic capture-SSD mounting.

- app.py: GTK3 fullscreen UI over cage — preview, REC/STOP, PHOTO,
  90-degree rotate button, tap-to-open exposure/gain/settings sliders,
  and an "SSD NOT MOUNTED" badge
- camera.py: picamera2 wrapper with separate video (ISP preview + packed
  12-bit raw) and still (4056x3040) configurations
- recorder.py: writer thread turning the raw stream into one Bayer frame
  per file plus index.jsonl/session.json, with dropped/missed accounting
- photos.py: still capture to DNG + JPEG, and a background worker that
  renders a viewable 16-bit sRGB TIFF from the 12-bit Bayer frame
- storage.py: SSD mount state and the date/time/format session layout
- tools/unpack_raw.py: desktop-side unpacker/demosaicer
- system/ + install.sh: systemd units, udev rule, mount helper, sudoers

Note: raw frames are written byte-for-byte as the sensor produced them, so
they stay decodeable regardless of how the stills pipeline evolves.

system/microscope-boot-check

@@ -0,0 +1,17 @@
+#!/bin/bash
+# One-shot boot verification: proves the kiosk came up and the SSD mounted.
+LOG=/home/tyler/boot-check.log
+export XDG_RUNTIME_DIR=/run/user/1000 WAYLAND_DISPLAY=wayland-0
+sleep 20
+{
+  echo "=== boot check $(date -Is) ==="
+  echo "camera service : $(systemctl is-active microscope-camera.service) (enabled: $(systemctl is-enabled microscope-camera.service))"
+  echo "ssd mount      : $(/usr/local/sbin/microscope-ssd status)"
+  echo "findmnt        : $(findmnt -no SOURCE,TARGET,FSTYPE /mnt/microscope || echo 'not mounted')"
+  echo "cage           : $(pgrep -a cage | head -1)"
+  echo "app            : $(pgrep -af 'python3 app.py' | head -1)"
+} >> "$LOG"
+for d in HDMI-A-1 HDMI-A-2 DSI-1 DPI-1 HDMI-1; do
+  if grim -o "$d" /home/tyler/boot-check.png 2>>"$LOG"; then echo "screenshot     : $d" >> "$LOG"; break; fi
+done
+chown tyler:tyler "$LOG" /home/tyler/boot-check.png 2>/dev/null