fix(ios): system-surface disclosure parity across selector routes

Follow-up to #2438 / #2448.

**Purpose.** The system-surface disclosure currently rides the snapshot `warnings`. Ensure it also surfaces on selector-backed routes (`find`/`wait`/`get`/`is`), matching the Android `systemSurfaceDisclosure` pattern, so the disclosure cannot silently drop on one route while surviving on another.

**Required behavior.** Route the disclosure through the shared selector response builder keyed off the capture's system-surface provenance (generalize `withSystemSurfaceDisclosure`), rather than only the direct snapshot warning path.

**Observable completion.** `get`/`is`/`find`/`wait` against a served sheet include the disclosure; a test asserts parity across routes.

**Dependencies.** #2448 (provenance + snapshot disclosure landed).