Move CI to Gitea: run-number offset, Cloudflare-only publishing

- plgVersionRunOffset=1000: stamped build number is run number + offset, so
  Gitea's restarted run counter cannot produce a versionCode below an
  installed one (GitHub reached prod 30, dev ~172). Tags and versionName use
  the same number.
- Drop the GitHub release steps; plg.wallacenet.ca is the only channel.

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01JdMNbY5hLR7FjtfEE712xG

.github/workflows/ci.yml

@@ -108,7 +108,10 @@ jobs:
           # it cannot name different versions.
           series="$(sed -n 's/^plgVersionSeries=//p' gradle.properties)"
           test -n "$series"
-          version="v${series}.${{ github.run_number }}-dev"
+          offset="$(sed -n 's/^plgVersionRunOffset=//p' gradle.properties)"
+          test -n "$offset"
+          # Same arithmetic as build.gradle.kts, so the tag names the APK's own number.
+          version="v${series}.$(( ${{ github.run_number }} + offset ))-dev"
           src="app/build/outputs/apk/debug/app-debug.apk"
           dest="ProLibertateGames-${version}.apk"
           cp "$src" "$dest"
@@ -124,27 +127,8 @@ jobs:
           if-no-files-found: error
           retention-days: 1
 
-      - name: Publish dev channel prerelease
-        if: github.ref == 'refs/heads/dev'
-        env:
-          GH_TOKEN: ${{ github.token }}
-        run: |
-          set -euo pipefail
-          gh release create "${{ steps.stage.outputs.version }}" \
-            "${{ steps.stage.outputs.apk }}" \
-            --repo "${{ github.repository }}" \
-            --target "${{ github.sha }}" \
-            --title "ProLibertateGames ${{ steps.stage.outputs.version }}" \
-            --prerelease \
-            --notes "Automated **dev channel** build from \`${{ github.sha }}\` on \`dev\`.
-
-          Preview build: newer than production, and less tested. Switch to the
-          Dev update channel in Settings to be offered these. Marked as a
-          prerelease so production-channel installs never see it."
-
-  # Publishes the build to https://plg.wallacenet.ca (Cloudflare Pages). Runs
-  # alongside the GitHub release above for one deployment so already-installed
-  # apps, which still read GitHub, can fetch the updater that reads Cloudflare.
+  # Publishes the build to https://plg.wallacenet.ca (Cloudflare Pages), which is
+  # the only release channel: the in-app updater reads latest.json from there.
   #
   # Both workflows deploy into one Pages site, and a deploy replaces the whole
   # site, so they share a concurrency group and never run at the same time.