docs: add VitePress documentation site with GitHub Pages deployment

Rewrites all documentation with accurate project details (Fastify, port
1349, single-container Docker, all 33+ tools, full database schema).
Adds getting started guide and configuration reference. Updates help and
settings dialogs to link to the docs site.

.github/workflows/deploy-docs.yml

@@ -0,0 +1,55 @@
+name: Deploy Docs to GitHub Pages
+
+on:
+  push:
+    branches: [main]
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+# Allow only one concurrent deployment, skipping runs queued between the run in-progress and latest queued.
+concurrency:
+  group: pages
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v3
+        with:
+          version: 9
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: pnpm
+      - name: Install dependencies
+        run: pnpm install
+      - name: Build Docs
+        run: pnpm --filter @stirling-image/docs docs:build
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: apps/docs/.vitepress/dist
+
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    needs: build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4