Add non-breaking presentation route baseline

[nishantmodak]

Goal

Establish the Week 1 non-breaking baseline before adding the public PMM handbook to this repository.

What changed

• Record 28 currently successful GitHub Pages routes with status, content type, response size, final URL, and source file.
• Record SHA-256 hashes for the root and 13 presentation HTML entry points.
• Record the current Pages configuration and the current 404 state of robots.txt, sitemap.xml, and llms.txt.
• Add a local baseline validator to the existing npm run check.
• Add Node 22 CI for pull requests and pushes to master.

No existing presentation, asset, or route was moved, renamed, deleted, or rewritten.

Verification

• Clean install with Node 22.21.0 and npm 10.9.4: npm ci --no-audit --no-fund
• npm run check
  • 15 HTML files: all local links resolve
  • 28 public routes, 14 content hashes, and 3 discovery endpoints validated
• All 28 recorded live routes returned HTTP 200 on 2026-10-09.

Baseline source

Captured from master commit 0f3b72ad28a41001604b74572368b505c7762378.