Polish settings, add matching defaults, drop pkg2zip, externalize infra config

- Rework Settings tab into grouped sections
- Add preferred-region matching and full-hash-by-default setting
- Replace combo-box square arrow with a proper chevron
- Fix UMD Refresh button (clicked bool was clearing the view)
- Remove pkg2zip.exe fallback (pure-Python decryptor is the primary path)
- Move LAN IP/share paths to .env; use example defaults in config

.env.example

@@ -0,0 +1,12 @@
+# Copy this file to `.env` and fill in your values. `.env` is git-ignored.
+
+# Static LAN IP for the API container on Unraid's macvlan bridge (br0).
+PSP_LAN_IP=192.168.10.100
+
+# Host paths mounted into the container (Unraid shares).
+PSP_STORE_HOST=/mnt/user/downloads/Sony - PlayStation Portable
+PSP_UMD_GAMES_HOST=/mnt/user/psp/umd_games
+PSP_UMD_VIDEOS_HOST=/mnt/user/psp/umd_videos
+
+# Secret token the desktop app sends as `Authorization: Bearer <token>`.
+PSP_API_TOKEN=