feat: add semver auto-increment and version display

- Add VERSION file (starts at 0.1.0)
- Deploy workflow bumps patch on every push, commits back [skip ci]
- APP_VERSION passed into container via env
- Version shown in page header next to title

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitea/workflows/deploy.yml

@@ -16,6 +16,23 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+        with:
+          token: ${{ secrets.GITEA_TOKEN }}
+
+      - name: Bump patch version
+        run: |
+          VERSION=$(cat VERSION)
+          MAJOR=$(echo $VERSION | cut -d. -f1)
+          MINOR=$(echo $VERSION | cut -d. -f2)
+          PATCH=$(echo $VERSION | cut -d. -f3)
+          NEW_VERSION="$MAJOR.$MINOR.$((PATCH + 1))"
+          echo $NEW_VERSION > VERSION
+          echo "APP_VERSION=$NEW_VERSION" >> $GITHUB_ENV
+          git config user.email "ci@domverse-berlin.eu"
+          git config user.name "CI"
+          git add VERSION
+          git commit -m "chore: bump version to $NEW_VERSION [skip ci]"
+          git push
 
       - name: Write .env
         run: |
@@ -23,11 +40,12 @@ jobs:
           OUTLINE_URL=http://172.29.0.13:3000
           OUTLINE_TOKEN=${{ secrets.OUTLINE_TOKEN }}
           TS_AUTHKEY=${{ secrets.TS_AUTHKEY }}
+          APP_VERSION=${{ env.APP_VERSION }}
           EOF
 
       - name: Deploy with docker compose
         run: |
-          echo "=== Deploying commit ${{ gitea.sha }} to ${{ gitea.ref_name }} ==="
+          echo "=== Deploying ${{ env.APP_VERSION }} (commit ${{ gitea.sha }}) to ${{ gitea.ref_name }} ==="
           docker compose -f "$COMPOSE_FILE" -p "$COMPOSE_PROJECT" up --build -d --remove-orphans
 
       - name: Prune dangling images