refactor(skills): move site-architecture catalogs to references

Keep the decision steps in SKILL.md and move catalogs, examples, and
checklists verbatim to references/ to reduce the context cost of loading the
skill.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

shared/skills/site-architecture/references/internal-linking.md

@@ -0,0 +1,43 @@
+# Internal Linking Strategy
+
+## Link Types
+
+| Type | Purpose | Example |
+|------|---------|---------|
+| Navigational | Move between sections | Header, footer, sidebar links |
+| Contextual | Related content within text | "Learn more about [analytics](/features/analytics)" |
+| Hub-and-spoke | Connect cluster content to hub | Blog posts linking to pillar page |
+| Cross-section | Connect related pages across sections | Feature page linking to related case study |
+
+## Internal Linking Rules
+
+1. **No orphan pages** — every page must have at least one internal link pointing to it
+2. **Descriptive anchor text** — "our analytics features" not "click here"
+3. **5-10 internal links per 1000 words** of content (approximate guideline)
+4. **Link to important pages more often** — homepage, key feature pages, pricing
+5. **Use breadcrumbs** — free internal links on every page
+6. **Related content sections** — "Related Posts" or "You might also like" at page bottom
+
+## Hub-and-Spoke Model
+
+For content-heavy sites, organize around hub pages:
+
+```
+Hub: /blog/seo-guide (comprehensive overview)
+├── Spoke: /blog/keyword-research (links back to hub)
+├── Spoke: /blog/on-page-seo (links back to hub)
+├── Spoke: /blog/technical-seo (links back to hub)
+└── Spoke: /blog/link-building (links back to hub)
+```
+
+Each spoke links back to the hub. The hub links to all spokes. Spokes link to each other where relevant.
+
+## Link Audit Checklist
+
+- [ ] Every page has at least one inbound internal link
+- [ ] No broken internal links (404s)
+- [ ] Anchor text is descriptive (not "click here" or "read more")
+- [ ] Important pages have the most inbound internal links
+- [ ] Breadcrumbs are implemented on all pages
+- [ ] Related content links exist on blog posts
+- [ ] Cross-section links connect features to case studies, blog to product pages