ci(release): idempotent registry publish — survive re-tagged releases

A moved release tag re-fires the publish workflows, and the Gitea
registries reject duplicate uploads with 409 (deb pool, rpm group, and
the generic packages' versioned URLs; the channel aliases already
pre-deleted). Delete any prior copy of the exact version before
uploading (404 on first publish tolerated), so a republished tag
overwrites instead of wedging — v0.5.0's retag left stale no-port-change
artifacts published and every re-run red.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.gitea/workflows/decky.yml

@@ -122,8 +122,13 @@ jobs:
           TOKEN: ${{ secrets.REGISTRY_TOKEN }}
         run: |
           BASE="https://$REGISTRY/api/packages/$OWNER/generic/$PACKAGE"
-          # 1) Immutable, versioned URL + its update manifest (the manifest's `artifact` points
-          #    here, so the published sha256 keeps matching what Decky later downloads).
+          # 1) Versioned URL + its update manifest (the manifest's `artifact` points here, so the
+          #    published sha256 keeps matching what Decky later downloads). A re-tagged release
+          #    re-fires this workflow and the registry 409s on duplicate uploads — delete any
+          #    prior copy of this version first (404 on the first publish is fine).
+          for f in punktfunk.zip manifest.json; do
+            curl -fsS -o /dev/null --user "enricobuehler:$TOKEN" -X DELETE "$BASE/$VERSION/$f" || true
+          done
           curl -fsS --user "enricobuehler:$TOKEN" --upload-file "$RUNNER_TEMP/punktfunk.zip" \
             "$BASE/$VERSION/punktfunk.zip"
           curl -fsS --user "enricobuehler:$TOKEN" --upload-file "$RUNNER_TEMP/manifest.json" \