ci: debounce the desktop build trigger to one bump per hour (matrix #9)

trigger-desktop checks the age of cinny-desktop's last main commit and
skips the submodule bump when it is under 60 minutes old; cinny-desktop's
new nightly catch-up workflow (or a manual dispatch) moves the submodule
to lotus HEAD for whatever landed inside the window. The desktop cadence
stops tracking every web commit, which was the biggest runner-load source.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

.gitea/workflows/ci.yml

@@ -132,11 +132,27 @@ jobs:
     if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/lotus' }}
     runs-on: ubuntu-latest
     steps:
+      # [matrix #9] Debounce: a Tauri build takes ~30 min on the shared runner,
+      # so at most one bump per DEBOUNCE_MIN. Commits that land inside the
+      # window are picked up by cinny-desktop's nightly catch-up workflow (or a
+      # manual dispatch of it) — the desktop cadence no longer tracks every web
+      # commit. The bump is also skipped when nothing changed.
       - name: Bump cinny submodule
         env:
           TOKEN: ${{ secrets.RELEASE_TOKEN }}
+          DEBOUNCE_MIN: '60'
         run: |
           CINNY_SHA="${{ github.sha }}"
+          LAST=$(curl -fsSL -H "Authorization: token $TOKEN" \
+            "https://code.lotusguild.org/api/v1/repos/LotusGuild/cinny-desktop/commits?sha=main&limit=1&stat=false&verification=false&files=false" \
+            | python3 -c 'import sys,json; c=json.load(sys.stdin); print(c[0]["commit"]["committer"]["date"] if c else "")' 2>/dev/null || true)
+          if [ -n "$LAST" ]; then
+            AGE=$(python3 -c "import sys,datetime; d=datetime.datetime.fromisoformat(sys.argv[1].replace('Z','+00:00')); print(int((datetime.datetime.now(datetime.timezone.utc)-d).total_seconds()//60))" "$LAST")
+            if [ "$AGE" -lt "$DEBOUNCE_MIN" ]; then
+              echo "Last desktop bump was ${AGE} min ago (< ${DEBOUNCE_MIN}); skipping — the nightly catch-up will pick this up."
+              exit 0
+            fi
+          fi
           git clone "https://x-access-token:$TOKEN@code.lotusguild.org/LotusGuild/cinny-desktop.git" desktop
           cd desktop
           git config user.email "ci@lotusguild.org"