fix(ai-seo): align with Google's official AI features optimization guide (#313)

Source: https://developers.google.com/search/docs/fundamentals/ai-optimization-guide

The skill was framed as "optimize for AI systems," which mis-states Google's
explicit position: AI Overviews and AI Mode are powered by core Search ranking,
so SEO best practices ARE the optimization strategy. Don't write separate
content "for AI."

The structural patterns the skill recommends (FAQ schema, comparison tables,
40-60 word answer blocks, llms.txt, /pricing.md) still help non-Google AI
engines (ChatGPT, Claude, Perplexity, Copilot) materially. The skill now
calls out the platform split explicitly rather than implying universal
benefit.

Major changes:

- New section "Google's Official Stance vs. Multi-Platform Reality":
  Frames Google's "don't optimize for AI" position alongside the reality that
  other AI engines reward extractable structure. Quotes Google's own
  phrasing.

- New section "Query Fan-Out (Google AI Search)":
  Explains Google's documented behavior of generating concurrent related
  queries. Reframes content strategy from per-query targeting to topical
  cluster coverage.

- New section "Agentic Experiences":
  Browser agents accessing sites via visual rendering, DOM inspection, and
  accessibility tree. Semantic HTML, JS-free meaningful render, clean a11y
  tree. Mentions the emerging Universal Commerce Protocol (UCP).

- New section "What NOT to Do":
  Explicit Google guidance: don't write for AI, don't chunk content for AI,
  don't scale variations (scaled content abuse spam policy), don't pursue
  inauthentic mentions, don't block AI crawlers if you want citation.

- Machine-Readable Files section reframed:
  Now opens with Google's stance ("not required") + the reason to include
  them anyway (non-Google AI engines).

- Schema markup note reframed:
  Notes Google's position that structured data is "not required for
  generative AI search" but still recommended.

- Search Console expectations added:
  Sets correct expectation that no AI-specific Search Console reporting
  exists; standard SEO metrics + third-party tools are the measurement
  options.

- Moved "AI SEO for Different Content Types" to references/content-types.md:
  Kept SKILL.md under 500 lines. Added a local-business/ecom subsection
  (Merchant Center + Google Business Profile + Business Agent) per
  Google's emphasis.

All 40 skills still pass validation.

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

skills/ai-seo/references/content-types.md

@@ -0,0 +1,71 @@
+# AI SEO by Content Type
+
+Tactical guidance for optimizing specific content types for AI search citation. These tactics work for non-Google AI engines (ChatGPT, Claude, Perplexity, Copilot) and don't hurt Google AI Overviews / AI Mode.
+
+For the cross-cutting strategy, see [SKILL.md](../SKILL.md).
+
+---
+
+## SaaS Product Pages
+
+**Goal:** Get cited in "What is [category]?" and "Best [category]" queries.
+
+**Optimize:**
+- Clear product description in first paragraph (what it does, who it's for)
+- Feature comparison tables (you vs. category, not just competitors)
+- Specific metrics ("processes 10,000 transactions/sec" not "blazing fast")
+- Customer count or social proof with numbers
+- Pricing transparency (AI cites pages with visible pricing) — add a `/pricing.md` file so AI agents can parse your plans without rendering your page (see "Machine-Readable Files" in the main skill)
+- FAQ section addressing common buyer questions
+
+---
+
+## Blog Content
+
+**Goal:** Get cited as an authoritative source on topics in your space.
+
+**Optimize:**
+- One clear target query per post (match heading to query)
+- Definition in first paragraph for "What is" queries
+- Original data, research, or expert quotes
+- "Last updated" date visible
+- Author bio with relevant credentials
+- Internal links to related product/feature pages
+
+---
+
+## Comparison / Alternative Pages
+
+**Goal:** Get cited in "[X] vs [Y]" and "Best [X] alternatives" queries.
+
+**Optimize:**
+- Structured comparison tables (not just prose)
+- Fair and balanced (AI penalizes obviously biased comparisons)
+- Specific criteria with ratings or scores
+- Updated pricing and feature data
+- Cite the `competitors` skill for building these pages
+
+---
+
+## Documentation / Help Content
+
+**Goal:** Get cited in "How to [X] with [your product]" queries.
+
+**Optimize:**
+- Step-by-step format with numbered lists
+- Code examples where relevant
+- HowTo schema markup
+- Screenshots with descriptive alt text
+- Clear prerequisites and expected outcomes
+
+---
+
+## Local Business / Ecom (Google emphasis)
+
+Google's AI features pull from product feeds and business profiles for local + ecom queries. Optimize:
+
+- **Merchant Center feeds** kept current with accurate inventory, pricing, attributes
+- **Google Business Profile** complete with hours, services, photos, posts, Q&A answered
+- **Reviews** — recent + sufficient volume; respond to reviews to signal active management
+- **Service area schema** for local services
+- **Business Agent** (where available) for conversational customer engagement