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

.gitea/workflows/release.yml

@@ -131,12 +131,19 @@ jobs:
             -PMINSTREL_VERSION_CODE=${{ steps.ver.outputs.code }}
 
       - name: Upload APK as workflow artifact
-        # @v3 because Gitea Actions emulates GHES and the v2 artifact
-        # backend used by upload-artifact@v4 errors with GHESNotSupportedError.
-        uses: actions/upload-artifact@v3
+        # Mirrored action, never actions/upload-artifact — @v4+ refuses on the
+        # hostname, @v3 uploads something Gitea will never serve back. This is
+        # the producing half of a pair: image-release downloads `minstrel-apk`
+        # below with the matching download-artifact mirror. Both must stay on
+        # the v4 protocol — mixing a v3 upload with a v4 download (or the
+        # reverse) yields an empty listing, not an error. See Scribe 2255 / 2270.
+        uses: https://git.fabledsword.com/bvandeusen/upload-artifact@cb8afe72b42edc798abfb8fcb556cf660d894245
         with:
           name: minstrel-apk
           path: android/app/build/outputs/apk/release/app-release.apk
+          # error, not the default warn: image-release hard-depends on this
+          # artifact existing, so an empty upload must fail here, not there.
+          if-no-files-found: error
 
       - name: Attach APK to gitea Release
         shell: bash
@@ -238,7 +245,14 @@ jobs:
         # Tag pushes only — android-release just produced this. Non-tag
         # builds take the "Bundle latest release APK" path below instead.
         if: steps.guard.outputs.ready == 'true' && startsWith(github.ref, 'refs/tags/v')
-        uses: actions/download-artifact@v3
+        # Consuming half of the pair — must match the upload's protocol, so it
+        # uses the download mirror, never actions/download-artifact. Same fork,
+        # same reason: upstream's client-side GHES check rejects this hostname
+        # before it connects. bvandeusen/download-artifact mirrors
+        # code.forgejo.org/forgejo/download-artifact; SHA below is its `v5` tag,
+        # the major matching the upload pin. Pinned, not tagged — the mirror
+        # auto-syncs every 8h and a moved tag would change what runs.
+        uses: https://git.fabledsword.com/bvandeusen/download-artifact@1314311ddb542af343a82d478ac786ceada4143a
         with:
           name: minstrel-apk
           path: client/

ci-requirements.md

@@ -44,4 +44,36 @@ None.
 - **Go toolchain pin.** `go.mod` is on `go 1.25.0` because `golang.org/x/crypto v0.51.0` declares 1.25 as its minimum. `ci-go:1.26` satisfies this with headroom. Future `x/crypto` bumps that move the Go floor should be paired with an image-tag bump in this file + the workflows.
 - **In-app update channel polling.** `release.yml` polls Gitea's release-asset API for up to 15 min on tag pushes to fetch the APK that `flutter.yml` is concurrently attaching to the same release. The asset eventually appears because `flutter.yml` and `release.yml` run in parallel on the same tag; if the polling times out, the server image ships without the bundled update channel (graceful degradation, not a build failure).
 - **Cache server reachability.** `test-web.yml` does NOT use `cache: 'npm'` on `actions/setup-node` — the Gitea Actions cache server isn't reachable from this runner's container network and `setup-node` was burning ~4m41s on ETIMEDOUT before failing open. With the migration to `ci-go:1.26`, `setup-node` is removed entirely (Node is in the image). The cache concern reappears if a future change re-introduces a network-dependent action.
+- **Artifacts — use the mirrored actions, never `actions/{upload,download}-artifact`.**
+  ```yaml
+  uses: https://git.fabledsword.com/bvandeusen/upload-artifact@cb8afe72b42edc798abfb8fcb556cf660d894245
+  uses: https://git.fabledsword.com/bvandeusen/download-artifact@1314311ddb542af343a82d478ac786ceada4143a
+  ```
+  Upstream's `@v4+` cannot work against this instance and no server-side change
+  will help: `isGhes()` rejects any hostname that isn't `github.com` /
+  `*.ghe.com` / `*.localhost` and throws before it opens a connection, so the
+  server is never asked what it supports. `@v3` is worse — it reports success,
+  and Gitea then serves artifacts back only through the v4 API
+  (`content_encoding = application/zip`), so a v3 upload is stored but invisible
+  to every retrieval path. A green job producing nothing retrievable; that is how
+  72 unreachable artifacts accumulated on this repo. Scribe issues 2255 / 2270.
+
+  Both are pull mirrors of the Forgejo project's forks
+  (`code.forgejo.org/forgejo/{upload,download}-artifact`, one commit on upstream
+  disabling that check), mirrored so CI depends on commits we hold and pinned by
+  SHA because the mirrors auto-sync every 8h — a moved upstream tag would
+  otherwise silently change what runs. The pins are upstream's `v5` tags on both
+  sides; **keep the majors matched.** `release.yml` is a producer/consumer pair —
+  `android-release` uploads `minstrel-apk`, `image-release` downloads it — and
+  mixing protocol versions across that pair yields an empty listing rather than
+  an error, which is the failure mode this whole entry exists to prevent.
+
+  Upload steps set `if-no-files-found: error` rather than the default `warn`, so
+  an upload that matches nothing fails its own job instead of failing the
+  consumer later.
+
+  Retrieval: `GET /api/v1/repos/{owner}/{repo}/actions/runs/{run_id}/artifacts`
+  for the id (global run id, not the repo-scoped run number), then
+  `…/actions/artifacts/{id}/zip`. The workstation has no `unzip` — use
+  `python3 -m zipfile -e`.
 - **Friction asks.** None pending. The two images cover everything Minstrel needs.