Fix deploy diff: use fetch-depth 0 so github.event.before is present locally

.gitea/workflows/deploy.yml

@@ -14,6 +14,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+        with:
+          # Full history: the deploy script diffs github.event.before..sha to
+          # find which files changed in this push. Shallow (depth-1, the default)
+          # clones don't contain the before commit, so that diff would 128.
+          fetch-depth: 0
 
       - name: Deploy changed files to WebDAV
         env: