feat: redesign admin panel & profile page, optimize Dockerfile, remove rootless

- Completely redesign admin.html matching OxiCloud design system
- Create standalone profile.html page with avatar, details & password change
- Optimize Dockerfile: 3-stage build, non-root user, OCI labels, layer cache
- Add .dockerignore to reduce build context
- Remove redundant Dockerfile.rootless & rootless-compose.yml
- Redesign login language selector as compact dropdown with search
- Fix CI/CD workflows (ci.yml, docker-build.yml, docker-publish.yml)
- Update app.js to navigate to profile page instead of modal

.github/workflows/docker-publish.yml

@@ -18,7 +18,7 @@ jobs:
     name: Pre-publish Tests
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
       - uses: Swatinem/rust-cache@v2
       - run: cargo test --workspace
@@ -30,7 +30,7 @@ jobs:
     needs: test
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Set version tag
         id: version
@@ -58,7 +58,7 @@ jobs:
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
       - name: Build and Push Multi-Arch Image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           platforms: linux/amd64,linux/arm64