v0.1.1 - Initial release flow!

Clean up README: fix typos, auth docs, logo, and env table (#134)

* Clean up README: fix typos, auth docs, logo, and env table

- Fix "behing" typo in contributing section
- Replace full-width animated SVG banner with smaller dark logo PNG
- Add placeholder for demo video embed
- Update auth row in tech stack to reflect both local and Clerk modes
- Clarify Quick Start prereqs (no Docker needed)
- Remove TinyFish/OpenRouter from .env table (entered via setup UI)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Add demo video thumbnail to README

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Reduce demo video thumbnail width to 400px

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Add demo video thumbnail with play button overlay

Full-width thumbnail with centered play icon linking to YouTube demo.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Make demo thumbnail play button larger with drop shadow

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix play button overlay using transparent PNG (no white square)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Rename thumbnail to bust GitHub image cache

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Update README.md

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Co-authored-by: Simantak Dabhade <simantak@mac.local>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>