Optimize Direct review and flatten knowledge routes

[zuiho-kai]

What changed

• route Direct reviews from PR title/body to compact owner/model quick maps
• emit early host progress and enforce bounded review command budgets
• add precise serving lifecycle, endpoint, and request/response code maps
• flatten component/model feature documents into their owner directories
• remove obsolete knowledge/_archive/ and knowledge/遗言/ content
• add knowledge-tree guards preventing guides/ layers under source owners

Why

Direct reviews were accurate but spent too much time navigating knowledge and repeating searches. The knowledge tree also forced readers through mechanical guides/_index.md hops before reaching a concrete feature page.

Strict compatibility is preserved: its fixed briefing files remain unchanged, and recursive doc_search/doc_read now resolve the flatter paths directly.

Validation

• 59 focused pytest tests passed
• Strict briefing smoke test passed
• doc_search("并行策略") resolves components/diffusion/parallelism.md
• knowledge tree validation passed
• wiki lint passed
• ruff passed
• git diff --check passed

Refs #24

[gemini-code-assist]

Caution

The consumer version of Gemini Code Assist on GitHub has been sunset. All code review activity has officially ceased.