定义 effect cleanup 生命周期 / Define the effect cleanup lifecycle

[tiye]

中文

用户可见结果

• 保留简洁的 state_effect("name", deps) { ... }，用于 focus、flash、日志等无需释放资源的 render 后工作。
• 新增 state_resource(name = ..., deps = ..., cleanup = ..., action = ...)，让 subscription、observer、timer handle 等 setup/cleanup 在严格类型下保持清晰，不要求 callback 返回两种不同形状。
• Effects demo 增加 lifecycle 示例与可观察 setup/cleanup 日志。

安全与生命周期

• deps 变化时，旧 cleanup 恰好执行一次并先于新 setup。
• ordinary component(...) unmount 与 reset_feature(...) 会释放对应 live resources。
• persistent feature_root(...) 仅因 route 暂时隐藏时保留 snapshot 与 live resource；显式 reset/runtime dispose 才释放。
• cleanup closure 只保存在 host memory registry，不进入 state tree、snapshot 或 localStorage。
• HMR 固定先 flush snapshot，再 dispose 旧 runtime，最后 boot 新 runtime；cleanup error 写入 [explore-react effect] 日志且不会阻断后续 setup/boot。

文档

• 新增 docs/effect-lifecycle.md，完整说明 author API、生命周期顺序、persistent feature policy 与 HMR hand-off。
• 同步 README、quick start、component author API、component lifecycle、PLAN 与开发指南。

验证

• yarn test:koka
• yarn build
• yarn check
• 浏览器验证 deps change 的 cleanup → setup 顺序。
• 浏览器验证 persistent route hide 不 cleanup。
• 真实 Vite HMR 验证旧 runtime cleanup、typed editor draft snapshot 恢复，以及返回 feature 后新 runtime setup。

关联 issue

Closes #18

English

User-visible result

• Keeps the concise state_effect("name", deps) { ... } form for focus, flash, logging, and other post-render work with nothing to release.
• Adds state_resource(name = ..., deps = ..., cleanup = ..., action = ...) so subscriptions, observers, timer handles, and other setup/cleanup lifecycles stay explicit under strict typing without requiring one callback to return two different shapes.
• Adds an Effects demo lifecycle case with observable setup/cleanup logging.

Safety and lifecycle

• On dependency changes, the old cleanup runs exactly once and before the new setup.
• Ordinary component(...) unmount and reset_feature(...) release their corresponding live resources.
• A persistent feature_root(...) retains both snapshot and live resource while temporarily hidden by routing; explicit reset or runtime disposal releases it.
• Cleanup closures stay only in the host memory registry and never enter the state tree, snapshot, or localStorage.
• HMR flushes the snapshot first, disposes the old runtime second, and boots the new runtime last. Cleanup errors are logged through [explore-react effect] and cannot block the following setup or boot.

Documentation

• Adds docs/effect-lifecycle.md with the complete author API, lifecycle order, persistent-feature policy, and HMR hand-off contract.
• Synchronizes the README, quick start, component author API, component lifecycle, PLAN, and developer guide.

Verification

• yarn test:koka
• yarn build
• yarn check
• Browser verification of cleanup → setup ordering on dependency changes.
• Browser verification that persistent route hiding does not clean up the resource.
• Real Vite HMR verification of old-runtime cleanup, typed editor-draft snapshot recovery, and new-runtime setup after returning to the feature.

Related issue

Closes #18