feat: add an Updates page that installs Stable, Nightly or test builds in-app (#98)

* feat: add an Updates page that installs Stable, Nightly or test builds in-app

* style: put update channels on the left and the build on one line

* style: make the update card read like a system updater

* feat: expand update notes, show the build beside the title, fit with button hints

* style: check for updates with the refresh icon Components uses

.github/workflows/build.yml

@@ -148,6 +148,8 @@ jobs:
             label="${BUILD_REF} at ${BUILD_SHA:0:7}"
           fi
           echo "label=$label" >> "$GITHUB_OUTPUT"
+          echo "DROIDDECK_SOURCE_COMMIT=${PR_HEAD_SHA:-$BUILD_SHA}" >> "$GITHUB_ENV"
+          echo "DROIDDECK_PR_NUMBER=${PR_NUMBER:-0}" >> "$GITHUB_ENV"
           echo "Build: \`$label\`" >> "$GITHUB_STEP_SUMMARY"
 
       - name: Cache the preloads

.github/workflows/pr-release-cleanup.yml

@@ -0,0 +1,39 @@
+name: PR Release Cleanup
+run-name: remove PR #${{ github.event.pull_request.number }}'s test build
+
+# A merged or closed PR's test build leaves DroidDeck-CI, so the app's Updates page stops offering it
+# (a merged fix is in the next Nightly). pull_request_target for the publisher app's secrets; nothing
+# from the PR is checked out or run.
+on:
+  pull_request_target:
+    types: [ closed ]
+    branches: [ main ]
+
+permissions: {}
+
+jobs:
+  cleanup:
+    runs-on: ubuntu-24.04
+    timeout-minutes: 5
+    steps:
+      # A token of the org's "DroidDeck CI Publisher" app, as build.yml's announce job uses.
+      - uses: actions/create-github-app-token@v2
+        id: ci-token
+        with:
+          app-id: ${{ vars.DROIDDECK_CI_APP_ID }}
+          private-key: ${{ secrets.DROIDDECK_CI_APP_KEY }}
+          owner: Droid-Deck
+          repositories: DroidDeck-CI
+      - name: Delete the test build
+        env:
+          GH_TOKEN: ${{ steps.ci-token.outputs.token }}
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+        run: |
+          set -euo pipefail
+          tag="pr-$PR_NUMBER"
+          if gh release view "$tag" -R Droid-Deck/DroidDeck-CI >/dev/null 2>&1; then
+            gh release delete "$tag" -R Droid-Deck/DroidDeck-CI --yes --cleanup-tag
+            echo "Deleted $tag"
+          else
+            echo "No test build for PR #$PR_NUMBER"
+          fi