Move `docs/defensive-patterns.md` into `docs/defensive-patterns/`, one page per
artifact plus a README router, and state each rule as its requirement, the
condition a reviewer judges it by, its boundary and approver, and a correct and
a wrong example.
- `general.md` (the moved page): the existing bug-class rules plus timing,
value representation, shared-state ownership, decentralization, performance
evidence, and migrations.
- `package-surface.md`, `remote-and-api.md`, `client-components.md`,
`conversation-and-session.md`: the review requirements for those artifacts,
linking type definitions and semantics to `docs/subsystems/` instead of
restating them.
- `README.md`: the habits behind the rules and the route from artifact to page.
- `dsh-code-review` reads the owning pages before judging a diff; the
`dsh-architecture-discipline` routing skill is retired in favour of the
directory, and every inbound reference is repaired.
- Chinese counterparts, pairing records, and the documentation tier table are
updated together.
