Share Cards, Public API, and Markdown Game Exports

This release adds three quality-of-life features aimed at sharing, integrations, and automation workflows. You can now share game snapshots more easily, consume analysis through a documented API, and fetch markdown directly for LLM pipelines.

Here's what's new:

• Share cards: Game pages now include a share card flow for quick posting and previews.
• Public API docs: The game endpoint is now documented at /docs/api with examples and response structure.
• Markdown export route: You can fetch game analysis as markdown by simply adding .md to the end of a game URL.

This should make it easier to share findings, build third-party integrations, and run VaporLens data through AI tooling without scraping HTML pages.