Merge human-owned Pursuit map

[RightL]

Review and land the human-owned Pursuit map implementation.

Key changes:

• simplify Pursuit to a human-owned Markdown graph
• add direct XMind-like map editing in the existing Web Studio
• add safe tree/storage operations, automatic F# backing, optimistic saves, and Git undo/redo
• remove Update's semantic write access to Pursuit
• add the explicit maintain-pursuit-map skill and align docs/examples

This PR is opened as draft while the implementation and CI are reviewed.

[RightL]

Review result: not ready to merge. 整体架构与已确定设计一致，但合并前需要修复以下问题：

1. 清理 Focus 占位文本。 新 starter 仍包含 No Pursuit is focused yet.；第一次 set_focus 只会追加引用，最终会同时出现“没有 Focus”和实际 Focus。新模板应使用空的 ## Focus。兼容旧 root 时，添加第一条 Focus 引用可仅删除完全匹配的历史占位句（且该 body 除空白外没有别的内容），不得删除用户自定义正文。增加从旧 starter 开始的回归测试。

2. 修复 Windows Web 启动失败清理。 native Windows CI 在 _terminate_owned_web_process 的 os.kill 上报 WinError 5 Access is denied。Windows 路径应在重新验证 PID identity 后使用可靠的 Windows process/tree termination（例如 taskkill /PID <pid> /T /F 或 handle-based termination），随后等待并证明进程退出；不要仅吞掉 PermissionError，也不要削弱 reused-PID identity fence。更新相应单元测试并让 native integration test 通过。

3. 修正 stale installer test。 test_rerun_preserves_managed_examples_and_user_state_byte_for_byte 仍替换/断言旧标题 Example Release Readiness，但新模板已没有该标题。改为替换当前实际存在的标题（例如 Example Application），同时保留 byte-for-byte preservation assertions。

4. 把前端校验接入 CI。 Ubuntu job 应运行 npm ci、npm run typecheck、npm test、npm run build，并确认提交的 rightmemory/web/static/pursuit-map.js、CSS 和 license 与构建结果一致，防止 TypeScript source 与随 wheel 分发的 bundle 漂移。

修复后重新跑完整 Linux/Windows workflow。Ubuntu 的 async worker timeout 看起来可能是独立的偶发问题；若重跑仍复现，再调查进程清理/测试隔离，不要直接忽略。

[RightL]

Update after reviewing current head 1f09da8: Windows Web shutdown fix is accepted; the latest Windows CI job now passes. Do not redo that work.

Remaining blockers before merge:

1. Remove the contradictory starter Focus placeholder and add backward-compatible first-focus cleanup exactly as described in the prior review.
2. Fix the stale Linux installer assertion (Example Release Readiness no longer exists; mutate/assert an actual current template title while retaining byte-preservation checks).
3. Add frontend npm ci / typecheck / tests / build / committed-bundle-diff verification to GitHub Actions.
4. The same detached async-worker shutdown timeout has now failed in two consecutive Ubuntu PR runs. It is no longer reasonable to treat it as a one-off. Investigate and fix the Linux process/test isolation issue, then require a fully green Linux/Windows workflow.

The implementation remains broadly sound; these are targeted finishing fixes, not a redesign.