Add integration tests for SDK→Bridge→Repository chain

12 integration tests covering:
- T4a: SDK packets/events propagate through bridges to repositories
- T4b: Connection lifecycle state transitions (connect/disconnect/reconnect)
- T4c: Error resilience (malformed protos, unknown ports, rapid fire, empty payloads)

Tests verify the full chain from FakeRadioTransport through RadioClient,
SdkStateBridge orchestration, and into service/node/topology repositories.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: jamesarich