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.

install.sh

@@ -0,0 +1,80 @@
+#!/bin/bash
+# Install the microscope camera kiosk and its storage plumbing onto this machine.
+#
+# This is the scripted form of what was originally set up by hand; running it on
+# a fresh Raspberry Pi OS install should reproduce the whole system:
+#
+#   sudo ./install.sh
+#
+# Everything it writes is listed in the README under "System integration".
+set -euo pipefail
+
+HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PREFIX="${PREFIX:-/opt/microscope-camera}"
+MOUNT_POINT="${MOUNT_POINT:-/mnt/microscope}"
+
+if [[ $EUID -ne 0 ]]; then
+    echo "run me with sudo" >&2
+    exit 1
+fi
+
+echo "==> packages"
+apt-get update
+apt-get install -y --no-install-recommends \
+    cage python3-gi python3-gi-cairo gir1.2-gtk-3.0 python3-cairo \
+    python3-picamera2 python3-pidng python3-simplejpeg python3-tifffile \
+    python3-pil python3-numpy grim
+
+echo "==> application -> $PREFIX"
+mkdir -p "$PREFIX"
+install -m 0644 "$HERE/app.py" "$HERE/camera.py" "$HERE/config.py" \
+               "$HERE/photos.py" "$HERE/recorder.py" "$HERE/storage.py" \
+               "$HERE/README.md" "$PREFIX/"
+if [[ ! -f "$PREFIX/config.json" ]]; then
+    install -m 0644 "$HERE/config.json" "$PREFIX/"
+fi
+mkdir -p "$PREFIX/tools"
+install -m 0755 "$HERE/tools/unpack_raw.py" "$PREFIX/tools/"
+chown -R tyler:tyler "$PREFIX"
+
+echo "==> SSD mount helper"
+install -m 0755 "$HERE/system/microscope-ssd" /usr/local/sbin/microscope-ssd
+install -m 0755 "$HERE/system/microscope-boot-check" /usr/local/sbin/microscope-boot-check
+
+echo "==> sudoers"
+install -m 0440 -o root -g root "$HERE/system/sudoers-microscope-ssd" \
+    /etc/sudoers.d/microscope-ssd
+
+echo "==> udev rule"
+install -m 0644 "$HERE/system/99-microscope-ssd.rules" \
+    /etc/udev/rules.d/99-microscope-ssd.rules
+
+echo "==> systemd units"
+install -m 0644 "$HERE/system/microscope-camera.service" \
+                "$HERE/system/microscope-ssd-mount.service" \
+                "$HERE/system/microscope-boot-check.service" \
+                /etc/systemd/system/
+
+echo "==> fstab (mount the capture SSD at boot when present)"
+if ! grep -q "$MOUNT_POINT" /etc/fstab; then
+    mkdir -p "$MOUNT_POINT"
+    UUID="$(blkid -s UUID -o value "$(lsblk -no PATH,LABEL | awk '$2=="MICROSCOPE"{print $1; exit}')" 2>/dev/null || true)"
+    if [[ -n "${UUID:-}" ]]; then
+        printf '\n# Microscope capture SSD - mounts automatically when plugged in\n'
+        printf 'UUID=%s  %s  ext4  nofail,noatime,errors=remount-ro,x-systemd.device-timeout=5  0  2\n' \
+            "$UUID" "$MOUNT_POINT" >> /etc/fstab
+    else
+        echo "   no MICROSCOPE-labelled partition found; add the fstab line by hand" >&2
+    fi
+fi
+
+echo "==> enable services"
+systemctl daemon-reload
+udevadm control --reload-rules
+systemctl enable microscope-camera.service microscope-boot-check.service
+systemctl restart microscope-camera.service
+
+echo
+echo "done. The kiosk should now be on the display."
+echo "  systemctl status microscope-camera.service"
+echo "  journalctl -u microscope-camera.service -f"