Add photo frame idle mode and switch to Skylight-style theme

- After 5 min of no touch/motion, dashboard hides behind a fullscreen
  photo slideshow with centered time and date overlay
- Photos loaded from PHOTOS_PATH env var (defaults to ~/Pictures/dashboard)
  via IPC + file:// URLs; traversal-guarded, recursive up to 2 levels
- Motion or touch exits idle back to dashboard
- Theme repainted warm cream / sage / stone ink with Nunito font and
  rounded cards; dark tokens kept so component classes still resolve
- Adds PHOTO_FRAME.md with Samba cifs mount + systemd env instructions

PHOTO_FRAME.md

@@ -0,0 +1,78 @@
+# Photo Frame (Digital Picture Frame)
+
+After `VITE_PHOTO_FRAME_IDLE_TIMEOUT` ms of no touch/mouse/keyboard activity
+(default 5 minutes), the dashboard is covered by a full-screen photo frame
+that cycles images from a local directory with a clock overlay. Touching the
+screen exits idle and returns to the dashboard. Motion detected by the
+Electron `MotionDetector` also cancels idle.
+
+## Photo source
+
+The Electron main process reads photos from the directory set in the
+`PHOTOS_PATH` environment variable. If unset, it falls back to
+`~/Pictures/dashboard`. Files are served via a `photo://` custom protocol
+so the renderer never exposes raw filesystem paths.
+
+Supported extensions: jpg, jpeg, png, webp, gif, heic, heif. Subdirectories
+are scanned up to two levels deep.
+
+## Mounting the Samba share on the kiosk
+
+On the kiosk (192.168.1.190):
+
+```bash
+# 1. Install cifs-utils
+sudo apt install -y cifs-utils
+
+# 2. Create a credentials file (chmod 600)
+sudo tee /etc/samba/credentials-dashboard <<'EOF'
+username=YOUR_SAMBA_USER
+password=YOUR_SAMBA_PASSWORD
+EOF
+sudo chmod 600 /etc/samba/credentials-dashboard
+
+# 3. Create mountpoint
+sudo mkdir -p /mnt/family-photos
+
+# 4. Add to /etc/fstab (replace server/share with actual values)
+echo '//SERVER_IP/SHARE_NAME /mnt/family-photos cifs credentials=/etc/samba/credentials-dashboard,uid=1000,gid=1000,iocharset=utf8,vers=3.0,ro,_netdev,x-systemd.automount 0 0' | sudo tee -a /etc/fstab
+
+# 5. Mount
+sudo mount -a
+ls /mnt/family-photos
+```
+
+## Pointing the app at the share
+
+Option A — systemd unit (if you run the app as a service):
+
+```ini
+# /etc/systemd/system/imperial-command-center.service (append to [Service])
+Environment=PHOTOS_PATH=/mnt/family-photos
+```
+
+Then `sudo systemctl daemon-reload && sudo systemctl restart imperial-command-center`.
+
+Option B — desktop launcher (if started from the GUI):
+
+Edit `~/Desktop/imperial-command-center.desktop` and set:
+
+```
+Exec=env PHOTOS_PATH=/mnt/family-photos /opt/imperial-command-center/imperial-command-center --no-sandbox --ozone-platform=wayland
+```
+
+Option C — shell wrapper used by current deployment:
+
+```bash
+sudo -u chrisryn PHOTOS_PATH=/mnt/family-photos \
+  XDG_RUNTIME_DIR=/run/user/1000 WAYLAND_DISPLAY=wayland-0 \
+  DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus \
+  /opt/imperial-command-center/imperial-command-center --no-sandbox --ozone-platform=wayland
+```
+
+## Tuning
+
+- `VITE_PHOTO_FRAME_IDLE_TIMEOUT` — idle timeout in ms (default 300000)
+- `VITE_PHOTO_FRAME_INTERVAL` — ms between photo transitions (default 15000)
+
+These are baked at build time.