ci: use Gitea variables for Coolify URL and app UUID

Move hardcoded values to repo variables:
- COOLIFY_URL: Coolify instance base URL
- COOLIFY_APP_UUID: application UUID to deploy

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -55,10 +55,10 @@ jobs:
 
       - name: Trigger Coolify deploy
         run: |
-          curl -s -X POST "https://coolify.jeanlucmakiola.de/api/v1/deploy" \
+          curl -s -X POST "${{ vars.COOLIFY_URL }}/api/v1/deploy" \
             -H "Authorization: Bearer ${{ secrets.COOLIFY_TOKEN }}" \
             -H "Content-Type: application/json" \
-            -d '{"uuid":"al88s5bflnej3m6h1rmr8ylq"}'
+            -d '{"uuid":"${{ vars.COOLIFY_APP_UUID }}"}'
 
   e2e:
     if: false  # E2E tests need rewrite: auth moved from local login to OIDC (Logto). Tests still expect username/password flow.