feat(docs): add YAML frontmatter to all docs (title/version/lastUpdated)

Every .md under docs/{architecture,guides,reference,frameworks,routing,
security,compression,ops,diagrams} plus docs/README.md now opens with:

  ---
  title: "<inferred from first H1>"
  version: 3.8.0
  lastUpdated: 2026-05-13
  ---

46 files updated (no docs were skipped — none had pre-existing
frontmatter). [slug]/page.tsx already reads frontmatter.version and
frontmatter.lastUpdated via gray-matter and renders a "v3.8.0" pill
plus a "Last updated" caption, so the UI picks these up automatically.

Helper: scripts/docs/add-frontmatter.mjs — idempotent (skips files that
already start with `---`), falls back to a humanized basename when no
leading H1 exists. Excludes docs/i18n/, docs/screenshots/,
docs/superpowers/, docs/diagrams/exported/. Re-runnable safely.

Also regenerated src/app/docs/lib/docs-auto-generated.ts: 44 docs across
8 sections (Architecture / Guides / Reference / Frameworks / Routing /
Security / Compression / Ops), which now includes the 14 docs that were
missing from the v3.7 sidebar (Cloud Agents, Guardrails, Memory, Skills,
Webhooks, Evals, Authz, Agent Protocols, Repository Map, Provider
Reference, Reasoning Replay, Stealth Guide, Tunnels Guide, Electron
Guide).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/compression/COMPRESSION_ENGINES.md

@@ -1,3 +1,9 @@
+---
+title: "Compression Engines"
+version: 3.8.0
+lastUpdated: 2026-05-13
+---
+
 # Compression Engines
 
 OmniRoute compression is built around engine contracts. A mode can run one engine directly