feat(ui): add git version info display in header

- Display current branch/tag and commit hash in navbar center
- Show dirty working directory indicator with yellow badge
- Add automatic build info generation in Task workflow
- Include build timestamp and user information
- Style with responsive design (hidden on mobile)
- Add .gitignore entries for generated build artifacts

layouts/partials/navbar-version.html

@@ -0,0 +1,17 @@
+{{/* Header version info - compact display in navbar */}}
+{{ $buildInfo := .Site.Data.build_info }}
+{{ if $buildInfo }}
+<div class="navbar-version-info d-none d-md-flex align-items-center">
+  <small class="text-light opacity-75">
+    {{ if $buildInfo.git_tag }}
+      <span class="fw-bold">{{ $buildInfo.git_tag }}</span>
+    {{ else }}
+      <span class="fw-bold">{{ $buildInfo.git_branch }}</span>
+    {{ end }}
+    <span class="mx-1">@</span><code class="text-light">{{ $buildInfo.git_commit_short }}</code>
+    {{ if $buildInfo.git_dirty }}
+      <span class="badge bg-warning text-dark ms-1 px-1" style="font-size: 0.6rem;">*</span>
+    {{ end }}
+  </small>
+</div>
+{{ end }}