Unbundle covers: fetch psppt-covers.zip from repo on demand with user prompt

README.md

@@ -79,8 +79,10 @@ pyinstaller --clean --noconfirm psppt.spec
 
 Notes:
 
-- The build bundles the DATs, PS1 loader, and the offline cover bundles. The
-  cover zips are large (~850 MB), so builds are slow and the output is big.
+- The build bundles the DATs, PS1 loader, cover templates, and index catalogs
+  (~80 MB total). The large offline cover zips (~850 MB) are **not** bundled —
+  the app fetches them on first run (see
+  [Offline bundles](#offline-bundles--auto-download)).
 - `7z` (p7zip-full on Linux, 7-Zip on Windows) is a **runtime** dependency for
   reading store archives — it is not bundled.
 - User data (credentials, manual covers, PS1 templates, NPS cache, library DB,
@@ -170,9 +172,10 @@ Discs are matched by hash first (most precise), then serial, then filename.
 - `data/credentials.json` — cover/metadata API keys (IGDB, TheMovieDB,
   ScreenScraper, Google Custom Search). Environment variables take precedence.
 - `data/manual_covers/games|videos/` — your own cover images.
-- `data/covers/` — checked-in assets: the UMD video/game cover templates,
-  `libretro-index.json` + `openvgdb-index.json` catalogs, `libretro-covers.zip` +
-  `openvgdb-covers.zip` offline cover bundles, and the legacy cover cache.
+- `data/covers/` — checked-in assets: the UMD video/game cover templates and
+  the `libretro-index.json` + `openvgdb-index.json` catalogs. The large
+  `libretro-covers.zip` + `openvgdb-covers.zip` bundles are git-ignored and
+  distributed as `psppt-covers.zip` (see above).
 - `data/base.PBP` — a PSN PS1 classic EBOOT (any game) supplying `STARTDAT`
   + a base `PARAM.SFO`/icon for PS1 conversion (git-ignored, copyrighted).
 - `data/loader/DATA.PSP` + `data/loader/KEYS.BIN` — bundled plain-ELF POPS
@@ -223,6 +226,7 @@ QSettings under `psppt`) taking precedence where noted.
 | `PSP_CREDENTIALS` | `$PSP_USER_DATA_DIR/credentials.json` | credentials file |
 | `PSP_LIBRETRO_COVERS_URL` | *(empty)* | direct URL for `libretro-covers.zip` (else derived from store server) |
 | `PSP_OVGDB_COVERS_URL` | *(empty)* | direct URL for `openvgdb-covers.zip` (else derived from store server) |
+| `PSP_COVERS_BUNDLE_URL` | Gitea `covers` release asset | combined `psppt-covers.zip` download URL |
 
 Cover/metadata keys can also be set as env vars: `IGDB_CLIENT_ID`,
 `IGDB_CLIENT_SECRET`, `TMDB_API_KEY`, `GOOGLE_API_KEY`, `GOOGLE_CX`,
@@ -255,12 +259,23 @@ Manual covers in `data/manual_covers/videos/` always win.
 
 ### Offline bundles & auto-download
 
-The two bundles (`libretro-covers.zip`, `openvgdb-covers.zip`) are shipped in
-`data/covers/`, so a fresh install works with **no internet and no API keys**.
-If either is missing at startup, the app downloads it from the store server's
-`/api/covers/<name>.zip` endpoint (see [Server setup](#server-setup)).
+The two bundles (`libretro-covers.zip`, `openvgdb-covers.zip`) are packaged
+into one `psppt-covers.zip` (~850 MB) and attached to the repo's `covers`
+release — **not** bundled into the app binary.
 
-Rebuild them yourself:
+On first launch, if the bundle isn't installed, the app asks whether to
+download it (with a progress bar). Covers keep working online via libretro /
+OpenVGDB / ScreenScraper / IGDB without it — the bundle just makes them instant
+and offline. "Don't ask again" is remembered, and you can re-download from
+**Settings → Cover sources → Download offline cover bundle…**.
+
+Build the bundle yourself:
+
+```bash
+python3 scripts/make-covers-bundle.py   # -> psppt-covers.zip
+```
+
+Rebuild the inner zips:
 
 ```bash
 python3 -m app.libretro          # libretro-thumbnails -> libretro-covers.zip