收敛 domain 与 component-store transition / Simplify domain and component-store transitions

[tiye]

中文

使用者可见结果

• 新增与 DOM event 无关的 action_store_transition(...)，表达“先发送一个完整 domain action，再按条件发送一个 component-store action”。
• Todo 的开始编辑、保存、取消三个 handler 从 15 行手写 owner-threading closure 收敛为 3 个声明式调用。
• Lab 的发送回复 handler 从 5 行 closure 收敛为 1 个声明式调用。
• click 与 Enter 继续复用同一个 transition 和现有 on_local_* listener，不新增按 event kind 排列的 helper 家族。
• 普通 domain-only 与 store-only 事件继续使用 on_action_* 和 on_store_*。

顺序与边界

• domain dispatch 永远先运行，因此 domain action payload、reducer effect 和 observation 顺序保持显式。
• store_when 只决定是否发送后续 component-store action，不会抑制 domain intent。
• 返回的 owner 始终来自 domain dispatch；domain reducer/workflow 仍然不能读取或修改 child store。
• 多个 store actions、effect response、复杂分支和直接 model 更新继续使用手写 on_local_* handler。

文档

• 新增 docs/action-store-transitions.md，分别说明中文和 English 的选择规则、顺序契约、示例与非目标。
• 更新 README、Agents.md 与 PLAN.md，补充推荐 API、公共 authoring surface 和 GitHub 跟踪状态。

验证

• yarn test:koka：70 项通过。
• yarn check 通过。
• 新增无真实浏览器依赖的 transition 顺序测试，验证 domain → component observation，以及 store_when = False 只跳过 component action。
• 浏览器 Todo：Enter 保存会提交 title 并结束 session；空 title 保持编辑；Cancel 正常恢复。
• 浏览器 Lab：Enter 回复会更新 incident，并清空 component draft。
• 浏览器无 warning 或 error。

English

User-visible outcome

• Add the DOM-event-independent action_store_transition(...) builder for one complete domain action followed conditionally by one component-store action.
• Collapse the three Todo start/save/cancel handlers from 15 lines of manual owner-threading closures into three declarative calls.
• Collapse the Lab send-reply handler from a five-line closure into one declarative call.
• Keep click and Enter on the same transition and existing on_local_* listeners instead of adding an event-kind helper family.
• Keep ordinary domain-only and store-only events on on_action_* and on_store_*.

Ordering and boundaries

• The domain dispatch always runs first, keeping the domain action payload, reducer effects, and observation order explicit.
• store_when controls only the following component-store action; it never suppresses the domain intent.
• The returned owner always comes from the domain dispatch. Domain reducers and workflows still cannot read or mutate child stores.
• Multiple store actions, effect responses, complex branching, and direct model updates remain handwritten on_local_* handlers.

Documentation

• Add docs/action-store-transitions.md with separate Chinese and English decision guides, ordering contracts, examples, and non-goals.
• Update README, Agents.md, and PLAN.md with the preferred API, public authoring surface, and GitHub tracking state.

Verification

• yarn test:koka: 70 passing.
• yarn check passes.
• Add a browser-independent transition ordering test for domain → component observation and for store_when = False skipping only the component action.
• Browser Todo: Enter saves the title and finishes the session; an empty title keeps editing active; Cancel restores normally.
• Browser Lab: Enter submits the reply and clears the component draft.
• No browser warnings or errors.

Closes #12

[Copilot]

Pull request overview

This PR introduces a small public helper in explore/react/state to express the common “dispatch one complete domain action, then optionally advance one component store action” pattern as a reusable, DOM-event-independent transition. It then migrates existing Todo/Lab handlers to this abstraction, and documents the intended decision/ordering contract.

Changes:

• Add action_store_transition(...) as an event-independent builder for domain → (optional) component-store transitions, preserving explicit ordering.
• Refactor Todo and Lab view handlers to reuse the new transition instead of handwritten owner-threading closures.
• Add documentation and a browser-independent test that asserts observation ordering and store_when = False behavior.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
README.md	Documents the new transition helper and clarifies when to use it vs on_local_*.
PLAN.md	Updates the authoring/API plan and status notes to reflect the new abstraction and rollout.
explore/react/state.kk	Adds action_store_transition(...) implementation alongside existing on_action_* / on_store_* helpers.
docs/action-store-transitions.md	New decision guide + ordering contract in Chinese and English with examples.
demo/todo/view.kk	Replaces start/save/cancel edit closures with action_store_transition(...) usage.
demo/tests/statecases.kk	Adds action_store_transition_test() to verify domain→component observation ordering and store_when semantics.
demo/tests.kk	Registers the new transition test in the demo test suite.
demo/lab/view.kk	Refactors send-reply handler to the new transition helper.
Agents.md	Updates contributor guidance to recommend action_store_transition(...) for the 1 domain + 1 store pattern.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.