ci: swap artifact upload+download to the mirrored actions (issue 2270)

android.yml and release.yml uploaded via actions/upload-artifact@v3, which
reports success while Gitea stores the result in a format its v4-only
artifact API will never serve back — 72 artifacts on this repo are on disk,
have valid DB rows, and are invisible to every retrieval path. Green jobs
producing nothing retrievable.

release.yml is a producer/consumer pair: android-release uploads
minstrel-apk and image-release downloads it to bundle into the container.
Swapping only the upload would have left download-artifact@v3 reading the
v1/v3 listing and finding nothing, so mirror the download side too —
bvandeusen/download-artifact, pull mirror of forgejo/download-artifact,
pinned at its v5 tag to match the upload pin's major.

Not actions/{upload,download}-artifact@v4: isGhes() throws on the hostname
before opening a connection, so no server-side change reaches it.

Upload steps also set if-no-files-found: error — image-release hard-depends
on minstrel-apk existing, so an empty upload must fail where it happens.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.gitea/workflows/android.yml

@@ -80,10 +80,16 @@ jobs:
 
       - name: Upload debug APK
         if: github.event_name == 'push' && github.ref == 'refs/heads/main'
-        # Gitea Actions runs in GHES-emulation mode; @actions/artifact v2+
-        # (i.e. upload-artifact@v4+) errors with "GHESNotSupportedError".
-        # Pin to @v3 until act_runner or the artifact backend catches up.
-        uses: actions/upload-artifact@v3
+        # Mirrored action, never actions/upload-artifact. @v4+ throws
+        # GHESNotSupportedError client-side on the hostname (no server setting
+        # reaches that check), and @v3 is worse — it reports success while Gitea
+        # serves artifacts back only through the v4 API, so the upload is stored
+        # and invisible to every retrieval path. @v3 is what left 72 unreachable
+        # artifacts on this repo. Pinned by SHA because the mirror auto-syncs;
+        # full URL because DEFAULT_ACTIONS_URL sends bare owner/repo to github.com.
+        # See Scribe issues 2255 / 2270.
+        uses: https://git.fabledsword.com/bvandeusen/upload-artifact@cb8afe72b42edc798abfb8fcb556cf660d894245
         with:
           name: minstrel-android-debug-${{ github.sha }}
           path: android/app/build/outputs/apk/debug/app-debug.apk
+          if-no-files-found: error