fix(ci): repair docs workflow broken since Feb 25 (YAML block scalar parse error)

[bensonwong]

Summary

• The docs deploy workflow (docs.yml) has been failing with "workflow file issue" on every run since 2026-02-25 — 200+ consecutive failures, zero deployments to GitHub Pages.
• Root cause: the script: | block in the preview-comment job uses YAML literal block scalar syntax. Its indentation level is set at 12 spaces by the first JS line. Two multi-line template literals (linkCheckSection and body) contained content at column 0 (e.g. <details>, plain prose, ---), which fell below the 12-space threshold and caused YAML to terminate the block scalar early. GitHub's parser then tried to interpret raw HTML/Markdown as YAML nodes and rejected the file.
• Fix: collapse both template literals to single-line strings with explicit \n escapes so every source line in the script stays within the 12-space YAML block indentation.
• Also fixes a subtle off-by-one: the original collapsed body was missing \n before ${linkCheckSection}, which would have dropped the blank line before --- when no lychee report is present.

Test plan

• Workflow run triggered by this PR's push should show jobs actually starting (not instant 0s failure)
• build job completes: Jekyll builds successfully, lychee link check runs
• preview-comment job posts a "📚 Documentation Preview" comment on this PR
• Link check section renders correctly when lychee report is present
• After merge to main, deploy job publishes to GitHub Pages

[claude]

📚 Documentation Preview

The documentation has been built successfully.

To preview locally:

1. Download the github-pages artifact from this workflow run
2. Extract and serve with any static file server:

   cd artifact && python -m http.server 8000

3. Open http://localhost:8000/deepcitation/

⚠️ Link Check Results

Click to expand link check report

Summary

Status	Count
🔍 Total	391
✅ Successful	336
⏳ Timeouts	0
🔀 Redirected	0
👻 Excluded	20
❓ Unknown	0
🚫 Errors	35

Errors per input

Errors in docs/_site/api-reference.html

• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found
• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found

Errors in docs/_site/types.html

• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found
• [404] https://fonts.gstatic.com/ | Cached: Error (cached)

Errors in docs/_site/getting-started.html

• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found
• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found

Errors in docs/_site/verification-statuses.html

• [404] https://fonts.gstatic.com/ | Cached: Error (cached)
• [404] https://fonts.googleapis.com/ | Cached: Error (cached)

Errors in docs/_site/frameworks/langchain.html

• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found
• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found

Errors in docs/_site/frameworks/vercel-ai-sdk.html

• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found
• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found

Errors in docs/_site/components.html

• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found
• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found

Errors in docs/_site/index.html

• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found
• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found

Errors in docs/_site/frameworks/index.html

• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found
• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found

Errors in docs/_site/frameworks/nextjs.html

• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found
• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found

Errors in docs/_site/CONTRIBUTING.html

• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found
• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found

Errors in docs/_site/error-handling.html

• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found
• [ERR] file:///home/runner/work/deepcitation/deepcitation/docs/_site/api-reference.md | Failed: Cannot find file
• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found
• [ERR] file:///home/runner/work/deepcitation/deepcitation/docs/_site/getting-started.md | Failed: Cannot find file
• [ERR] file:///home/runner/work/deepcitation/deepcitation/docs/_site/styling.md | Failed: Cannot find file

Errors in docs/_site/code-examples.html

• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found
• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found

Errors in docs/_site/styling.html

• [404] https://fonts.gstatic.com/ | Cached: Error (cached)
• [404] https://fonts.googleapis.com/ | Cached: Error (cached)

Errors in docs/_site/404.html

• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found
• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found

Errors in docs/_site/curl-guide.html

• [404] https://fonts.googleapis.com/ | Failed: Network error: Not Found
• [404] https://fonts.gstatic.com/ | Failed: Network error: Not Found
  Full Github Actions output

---

Workflow run: 23135460134

[github-actions]

❌ Playwright Test Report

Status: Tests failed

📊 Download Report & Snapshots (see Artifacts section)

What's in the Visual Snapshots

The gallery includes visual snapshots for:

• 🖥️ Desktop showcase (all variants × all states)
• 📱 Mobile showcase (iPhone SE viewport)
• 📟 Tablet showcase (iPad viewport)
• 🔍 Popover states (verified, partial, not found)
• 🔗 URL citation variants

---

Run ID: 23135460145