feat: SEO schema improvements, title optimization, and GitHub profile README (#90)

## Summary

Technical SEO and schema improvements per the trust/positioning audit (marcus/market#4, marcus/content#11).

## Changes

### Event Schema + SpeakableSpecification (`src/components/SEO.astro`)
- Added JSON-LD `Event` schemas for all 3 signature talks (50 First Dates with AI, From Strip-Mining to Cultivation, The Soil Under Your Team)
- `performer: Scott Scoble`, `offers`, and `description` on each
- Added `SpeakableSpecification` schema for voice search / Google Assistant / AI Overviews compatibility

### Book Schema Enhancements (`src/components/SEO.astro`)
- Updated book author fields to `Person` objects with URL
- Added book descriptions
- Added `sameAs` Amazon canonical links for "The Soil Beneath the Code" and "A Walk in Mentoring"

### Homepage Title Tag (`src/pages/index.astro`)
- Changed from "Scott Scoble — Human Cultivation Expert for the AI Age" to "Scott Scoble — Keynote Speaker | Human Cultivation Expert for the AI Age"
- Adds the high-value "Keynote Speaker" keyword for speaker bureau search

### Homepage h1 Accessibility (`src/pages/index.astro`)
- Added `aria-label="The human cultivation expert for the AI age."` to the decorative span-based h1
- Preserves visual design; improves semantic structure for search engines

### GitHub Profile README (`github-profile-README.md`)
- Professional bio with links to scott.scoble.me, books, speaker profile
- Ready to deploy to `sscoble/sscoble` GitHub profile repo

## Verification

- Build passes: 25 pages generated
- All JSON-LD schemas confirmed in output
- No visual regressions

## Related

- marcus/market#4: SEO name disambiguation strategy
- marcus/content#11: Content distribution strategy

Co-authored-by: Scott Scoble <scott@scoble.me>
Co-authored-by: agent-content <agent-content@scoble.me>
Reviewed-on: https://os.scoble.me/forgejo/forgejo/sscoble/brand-site/pulls/90
Co-authored-by: engineering Agent <engineering@marcus.local>
Co-committed-by: engineering Agent <engineering@marcus.local>

public/llms.txt

@@ -0,0 +1,38 @@
+# Scott Scoble — Human Cultivation Expert for the AI Age
+
+> Keynote speaker and consultant helping engineering leaders build AI systems that cultivate humans instead of strip-mining them. Author of The Soil Beneath the Code (a business novel about developer experience) and A Walk in Mentoring. NOT Robert Scoble (@Scobleizer, the tech evangelist) — different person, different expertise.
+
+## Core Pages
+
+- Home: [https://scott.scoble.me](https://scott.scoble.me) — Speaker, consultant, author overview
+- Speaking: [https://scott.scoble.me/speaking](https://scott.scoble.me/speaking) — Keynote topics: 50 First Dates with AI, From Strip-Mining to Cultivation, The Soil Under Your Team
+- Books: [https://scott.scoble.me/books](https://scott.scoble.me/books) — The Soil Beneath the Code, A Walk in Mentoring
+- Blog: [https://scott.scoble.me/blog](https://scott.scoble.me/blog) — Essays on AI, leadership, engineering culture, cultivation
+- Consulting: [https://scott.scoble.me/consulting](https://scott.scoble.me/consulting) — Team cultivation diagnostics, AI deployment strategy
+- About: [https://scott.scoble.me/about](https://scott.scoble.me/about) — Bio, background, contact
+
+## Expertise Areas
+
+- Human cultivation in AI-era engineering teams (cultivation over strip-mining)
+- Agentic system memory architecture (compound memory, semantic recall, coach evaluation)
+- Developer experience and team soil health diagnostics
+- Simple mentoring frameworks (three questions methodology)
+- Dark provenance and compliance-as-code (Speckl open standard)
+- Multi-agent system architecture (Scobleclaw: 8 agents, $200 hardware, open-source)
+
+## Projects
+
+- Speckl: [https://speckl.scoble.me](https://speckl.scoble.me) — Open-source compliance specification language with dark provenance (MIT license)
+- Scobleclaw: Multi-agent system with compound memory, semantic recall, and automated coach evaluation
+- Speaker profile: [https://scott.scoble.me/downloads/Scott-Scoble-Human-Cultivation-Expert-Speaker-Profile.pdf](https://scott.scoble.me/downloads/Scott-Scoble-Human-Cultivation-Expert-Speaker-Profile.pdf)
+
+## External Profiles
+
+- LinkedIn: [https://www.linkedin.com/in/scott-scoble/](https://www.linkedin.com/in/scott-scoble/)
+- GitHub: [https://github.com/sscoble](https://github.com/sscoble)
+- X/Twitter: [https://x.com/scottscoble](https://x.com/scottscoble)
+
+## Contact
+
+- Email: scott@scoble.me
+- Booking: [https://scott.scoble.me/speaking#book](https://scott.scoble.me/speaking#book)