fix: declare resolved audio route in server info

[morozsm]

Explicit release repair: /api/v1/info omitted the active audio route, leaving remote consumers unable to select a route. Add canonical audioRoute from the existing resolver, or null without an attached radio. Existing fields and protocol version 1 remain unchanged.

The diff against current main d786ffd9f2675c1538982b737e683d83f40da9ea contains exactly src/rigplane/web/server.py and tests/test_web_server.py. Literal HTTP regressions cover serial, explicit USB, LAN DATA policies, unknown and disconnected backends, and no radio.

Focused verification used a separate pinned ref based on packaged Core 2d390312e7a4d646eed9b9e8e7ec12c376e17f17:

• Corrected RED, test-only 19f4cd3250fa9c619368ec09f4f23dd2792b0942: 10 missing-audioRoute failures, 39 passed, 1 skipped.
• GREEN, pinned repair fe08ea50b501838df178ea959d23911bc500981f: 49 passed, 1 skipped; scoped Ruff check/format passed. The test file is byte-identical between these heads.
• Consumer GREEN, frozen Pro cd9abf15e221a1c7e04831d69b3c93daa43d9c97 bound to that pinned repair: 83 passed, 0 skipped.

The main candidate carries the same repair via ordinary cherry-picks and includes main's seven unrelated commits beyond packaged Core2d. It is a separate source candidate; focused pinned evidence does not replace this Ready head's required CI or establish a new packaged tuple, native audio, or hardware acceptance.

[morozsm]

Agent Review: PASS 4221410

Independent source review: the two-file patch adds canonical audioRoute using the existing resolver/dataclass, with null for no radio. Literal endpoint cases cover serial/USB, LAN policies, unknown/disconnected and no-radio output while preserving protocol 1 and readiness fields. No blocking source finding; the resolver, auth, leases and TX policy remain unchanged.

The main patch is identical to separately reviewed pinned fe08ea5; its seven later base commits are not admitted packaged scope. Coordinator reports pinned focused GREEN 49 passed/1 skipped and locked scoped Ruff PASS; required current-head PR CI remains separate. This code verdict does not certify native audio, automatic enable, hardware or a new release tuple.