feat(client): show git-describe version next to the brand logo

Display the app version (output of `git describe --tags`) in the header
beside the gitmost logo: a clean tag renders as `vX.Y.Z`, otherwise the
tag plus commits-since and short hash (e.g. v0.90.1-56-g25975acd).

- vite.config.ts: resolve APP_VERSION from env (Docker/CI) -> git describe
  (local) -> package.json version fallback
- app-header.tsx: render APP_VERSION after the brand block (ml="md"),
  nudge the Home nav group (ml={50} -> "xl")
- Dockerfile: accept APP_VERSION build-arg in the builder stage (.git is
  excluded from the build context)
- CI: pass APP_VERSION build-arg — release.yml uses the tag, develop.yml
  computes git describe with fetch-depth: 0
- nx.json: add APP_VERSION to the build target inputs so the cache
  invalidates when the version changes

.github/workflows/develop.yml

@@ -23,6 +23,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
@@ -34,11 +36,17 @@ jobs:
           username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Resolve version
+        id: version
+        run: echo "value=$(git describe --tags --always)" >> "$GITHUB_OUTPUT"
+
       - name: Build and push develop image
         uses: docker/build-push-action@v6
         with:
           context: .
           platforms: linux/amd64
+          build-args: |
+            APP_VERSION=${{ steps.version.outputs.value }}
           push: true
           tags: ${{ env.IMAGE }}:develop
           cache-from: type=gha,scope=develop-amd64