fix(capabilities): recognize leading Chinese delegation

[tt-a1i]

Summary

• recognize sentence-initial Chinese delegation requests such as 子代理了解下项目
• require an execution verb after the leading capability name instead of treating every Chinese mention as authorization
• keep UI highlighting and runtime activation on the same shared intent seam
• document the explicit Chinese trigger and its discussion/negation/conditional boundaries

Validation

• regression test first reproduced 子代理了解下项目 -> []
• focused intent, activation, and UI tests: 25 passed, 0 failed
• bun run check
• bun run test (Node 890 passed; Vitest 30 passed)
• git diff --check

No manual TUI smoke is claimed because the installed OpenPI runtime does not point at this checkout.

Closes #121