…rewrite

- Fold Features and Workflows into the Guides hub as cards; drop their
  separate top-nav links site-wide (index, features, workflows, guides,
  manual, blog, all guide + blog subpages now use Guides as the umbrella).
- Trim the Features 'workspace in action' use cases to the four that show
  genuine capability; renumber 01-04.
- Add docs/content-style-guide.md: pitch-derived voice, canonical
  vocabulary, hook formula, per-type templates, SEO/AEO checklist.
- Pilot the guide on what-is-ai-aware-version-control: contrast hook,
  answer-first TL;DR callout, question headings, FAQPage JSON-LD
  (schema<->visible parity), fixed duplicate title suffix, bumped
  dateModified.

- New _static/highlight.js: dependency-free, left-to-right sticky-regex
  lexer for bash/shell, yaml, json, toml/ini. Forward-only scan over
  decoded text with re-escaping on output, so it cannot mangle markup
  (verified: 74 real blocks highlighted, 0 integrity failures).
- New _static/highlight.css: tokens themed to the monochrome+red palette
  (h5i/keys red, flags/vars cyan, strings green, comments faint), with
  literal fallbacks for pages missing a var.
- Targets <pre><code class="language-*"> (the Manual, 69 blocks) and plain
  .terminal-body <pre> blocks; skips hand-authored terminal blocks that
  already carry t-* spans, and leaves unknown languages untouched.
- Wired the CSS+JS into all 41 pages (deferred, idempotent).

- Render command words (incl. h5i) uniformly white instead of red; the red
  $ prompt stays the single accent, matching the existing terminal style
  (t-cmd white / t-prompt red). Drops the now-unused hl-builtin style.
- Highlight <pre><code> blocks with no language hint when they read like
  shell (conservative heuristic: command/comment-led lines, no rendered
  output/diagram glyphs). Manual coverage 68 -> 137 blocks; the 30
  output/box-diagram blocks are correctly skipped.
- Broaden the terminal selector to .terminal pre (still skips hand-authored
  blocks via the child-span guard). Verified 0 integrity failures across
  manual + front page + guides + blog.