feat: add reviews content collection

Move all 24 review entries from skills-review/catalog.js +
skills-review/submitted-catalog.js into a typed Astro content collection at
src/content/reviews/. Each entry is a Markdown file with frontmatter for the
review metadata (id, author, focus, wins, improve, extras, name, description)
and a body that holds the 'improved' SKILL.md content.

Re-point scripts/build-skill-review.mjs at the new collection. The generator
reads each .md file, parses its YAML frontmatter, and writes
skill-reviews/improved/{id}/SKILL.md in the same shape the legacy catalog
produced — verified byte-identical via 'git diff --exit-code skill-reviews/'.

The 'name' field is preserved separately from 'id' because two entries
renamed the skill during review (id angular-accessibility-root → name
angular-accessibility; id confectionary-skill-hub → name confectionery-orders).
Without it the generator output would drift on those two files.

Does not yet delete skills-review/catalog.js or submitted-catalog.js —
verify.mjs and the legacy review-desk page both still read them, so they
stay as a mirror until task 16 rewires the page to the collection. Adding a
new submission today requires editing both the .md file (new source of
truth) and the legacy catalog.js (until task 16).

Done-when:
- 24 entries under src/content/reviews/ ✓
- verify.mjs's id:' count assertion still passes ✓
- git diff --exit-code skill-reviews/ clean after regenerating ✓
- astro check passes (22 files: 0 errors, 0 warnings, 2 hints) ✓

Co-Authored-By: Claude Code <noreply@anthropic.com>

src/content/reviews/page-reviewer.md

@@ -0,0 +1,55 @@
+---
+author: 'Marcos Silva'
+description:
+  'Review a Confluence-ready draft and its posting context before publication.
+  Use when a user wants an evidence-backed PASS, REVISE, or BLOCK verdict; this
+  skill never publishes or edits a page.'
+extras:
+  'Publish a compact machine-readable finding schema so the dry-run script and
+  human review agree.'
+focus:
+  'Review a Confluence draft before publishing and provide an evidence-backed
+  verdict.'
+id: 'page-reviewer'
+improve:
+  - 'Make connector-dependent checks conditional and state the fallback when the
+    connector is unavailable.'
+  - 'Clarify which internal links and hostnames are permitted instead of using a
+    broad suffix exception.'
+  - 'Add deterministic fixtures for secrets, title collisions, and invalid
+    macros.'
+name: 'page-reviewer'
+path: '../submitted-skills/Marcos%20Silva/skills/page-reviewer/SKILL.md'
+status: 'Strong non-mutating gate'
+title: 'Page reviewer'
+wins:
+  - 'Clear PASS / REVISE / BLOCK model with anchored findings.'
+  - 'Non-mutating scope and optional PlantUML checks are well defined.'
+---
+
+# page-reviewer
+
+## Inputs
+
+Draft body, intended space/title/parent, and any available approved connector
+context.
+
+## Workflow
+
+1. Run deterministic local checks for content safety, storage structure, links,
+   and diagram markup.
+2. If an approved connector is available, check title and target context;
+   otherwise report that check as unavailable.
+3. Anchor every finding to a line or section and issue PASS, REVISE, or BLOCK.
+
+## Rules
+
+- Never publish, edit, or treat placeholders as safe secrets.
+- Distinguish allowed internal destinations from unverified hosts using the
+  project policy.
+- A missing required validation is a stated limitation, not a pass.
+
+## Output
+
+Return verdict, scope, findings (severity, anchor, evidence, action), checks
+run, and the next safe step.