Release v0.3.0 with revision-consistent agent context

[mengshi02]

Summary

• add deterministic brief context packs across Go API, CLI, and MCP
• add revision-consistent incremental indexing, filesystem watch mode, recovery, and clean-full equivalence gates
• improve Go and TypeScript semantic precision and promote them to Stable
• add reproducible competitive and live-context benchmarks
• update English/Chinese documentation, changelog, release workflow, and version to 0.3.0

Why

v0.3.0 closes the coding-agent loop: understand code, edit it, refresh the graph, and continue querying one complete revision without mixed source/graph state.

User impact

• brief replaces repeated search/read/caller/test loops with one bounded context pack
• mcp --watch automatically refreshes indexed repositories after edits
• graph, symbol, source, vector invalidation, and metadata publish atomically
• five-run Gin benchmark observed zero mixed revisions and 67%–75% fewer product tool round trips than the tested CodeGraph/CBM workflows

Validation

• make release-gate
• Python benchmark script compilation
• Markdown local-link and benchmark JSON validation
• staged whitespace and sensitive-path scan
• five-run clean-full-equivalent Gin live-context benchmark

[mengshi02]

v0.3.0 release review is ready.

All release gates have passed, including unit tests, go vet, Go/TypeScript quality gates, incremental-versus-clean-full equivalence tests, and the live-context benchmark.

Ready for final review and merge.