docs: Complete migration to HTML with Diataxis framework and add SVG diagrams

- Migrate 8 markdown files to 21 HTML pages following Diataxis framework:
  * 5 Tutorials (learning-oriented): deployment-guide, shared-storage-quickstart,
    gpu-workers, dataset-mounting, general-mounting
  * 6 How-To Guides (task-oriented): scale-workers, upgrade-concourse,
    configure-gpu, setup-shared-storage, monitor-prometheus, troubleshoot
  * 6 Reference pages (information-oriented): configuration, deployment-modes,
    relations, architecture, test-matrix, rocm-verification
  * 4 Explanation pages (understanding-oriented): shared-storage,
    key-distribution, gpu-architecture, container-runtime

- Add 6 professional SVG diagrams replacing ASCII art:
  * TSA authentication flow with reverse tunnel (key-distribution.html)
  * Peer relation vs TSA/Flight relation comparison (key-distribution.html)
  * GPU container creation flow with runc wrapper (gpu-architecture.html)
  * Automatic upgrade sequence timeline (upgrade-concourse.html)
  * LXC UID/GID mapping with shift=true (shared-storage.html)

- Fix all prometheus/grafana charm references:
  * Use prometheus-machine and grafana-machine in deploy commands
  * Maintain app names (prometheus, grafana) in relation endpoints
  * Updated in configuration.html and relations.html

- Remove deprecated mode=all from all documentation

- Add GitHub Pages workflow for documentation hosting

- Delete 8 original markdown files after successful migration:
  deployment-guide.md, quickstart-shared-storage.md, gpu-support.md,
  dataset-mounting.md, general-mounting.md, shared-storage.md,
  ROCM_VERIFICATION.md, test-matrix.md

- Update AGENTS.md with documentation structure

- Update deploy-test.sh and shared-storage plan

Breaking changes: Documentation now requires browser to view (HTML instead of markdown)

Author: fourdollars

.github/workflows/pages.yml

@@ -0,0 +1,45 @@
+name: Deploy GitHub Pages
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - 'docs/**'
+      - '.github/workflows/pages.yml'
+  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.
+# However, do NOT cancel in-progress runs as we want to allow these production deployments to complete.
+concurrency:
+  group: "pages"
+  cancel-in-progress: false
+
+jobs:
+  deploy:
+    name: Deploy to GitHub Pages
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Pages
+        uses: actions/configure-pages@v5
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: ./docs
+
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

AGENTS.md

@@ -81,11 +81,11 @@ The `deploy-test.sh` script handles the entire lifecycle: build, deploy, verify,
 ### Manual Deploy & Test (Local LXD)
 ```bash
 # 1. Bootstrap a test controller (if not exists)
-# Note: --config test-mode=true sets update-status-hook-interval to 10s (vs 5m) for faster feedback
-juju bootstrap localhost test-controller --config test-mode=true
+juju bootstrap localhost test-controller
 
 # 2. Deploy PostgreSQL (REQUIRED: 16/stable)
-juju add-model concourse-test
+# Note: --config test-mode=true sets update-status-hook-interval to 10s (vs 5m) for faster feedback
+juju add-model concourse-test --config test-mode=true
 juju deploy postgresql --channel 16/stable
 
 # 3. Deploy Concourse (Auto-Scaling Mode)