Bilingual docs & marketing site

The AIEO.ee docs and website are new, in both languages:

• Product docs at /docs — getting started, SEO intelligence, gap analysis, AI visibility, site audit, the Growth Agent, developer guides and billing — 32 pages, every one in English and 简体中文.
• A generated developer reference — the API route inventory and the MCP tools reference are generated from the running app, with a CI gate that fails when they drift from the code.
• The commercial site — pricing from the same single source of truth as the product's plan table, feature and use-case pages, and honest labels on every claim (sampled engines are marked as sampled here, too).

Full-text search works in both languages, docs pages expose a markdown version (.md, plus llms.txt for AI agents).