Changelog

All non-WebUI user-visible changes. Newest version on top.

[Unreleased]

Repo structure conformed to AGENTS.md: web/ renamed to frontend/; backend HTTP layer moved from internal/api to cmd/webui/{api,handlers} (cmd/server → cmd/webui); README/CHANGELOGs relocated under docs/ (README_zh.md added as Chinese mirror); module-level .gitignores added (backend/, deploy/); stray root library/ removed (book files live in deploy/api/storage/); debug binaries untracked.
Docs: docs/README.md is now the English primary; previous Chinese README mirrored to docs/README_zh.md.