fix(NetworkChangeManager): classify transport from activeNetwork, not per-callback caps

[torlando-agent]

Implements the approved plan for #898.

Summary

NetworkChangeManager.onCapabilitiesChanged at app/src/main/java/network/columba/app/service/manager/NetworkChangeManager.kt:104 calls emitTransportIfChanged(currentTransportOf(networkCapabilities)), classifying the transport from the per-callback NetworkCapabilities. The NetworkCallback is registered against NET_CAPABILITY_INTERNET, which fires for every network matching the request — not just the system-default route. On a dual-radio device (Wi-Fi default + cellular kept up as backup) the cellular network's capability update gets classified as CELLULAR and emitted as a transport change while Wi-Fi remains the active route.

Currently latent: ServiceModule.createManagers is invoked from ReticulumService.onCreate (ReticulumService.kt:59) without an onTransportChanged consumer, so the misclassified emission goes nowhere. Should be fixed before any service-process consumer relies on the callback.

Changes

• app/src/main/java/network/columba/app/service/manager/NetworkChangeManager.kt — onCapabilitiesChanged now classifies the transport via the existing currentTransportOf(connectivityManager) helper (reads connectivityManager.activeNetwork then its capabilities), mirroring the PR feat(InterfaceConfig): per-interface Wi-Fi/cellular network restriction #896 fix in InterfaceTransportObserver. The per-callback network/networkCapabilities parameters remain (still feed the Log.v line and are required by the framework signature). Comment block above the call was rewritten to describe the activeNetwork-classification rationale.
• app/src/test/java/network/columba/app/service/manager/NetworkChangeManagerTest.kt — capability-driven tests now stub connectivityManager.activeNetwork and connectivityManager.getNetworkCapabilities(network) before each onCapabilitiesChanged(...) invocation. Added onCapabilitiesChanged cellular backup on wifi default does not flip transport covering the dual-radio repro.

Test plan

• ./gradlew :app:testNoSentryDebugUnitTest --tests "network.columba.app.service.manager.NetworkChangeManagerTest" — 18/18 pass, including the new dual-radio repro.
• ./gradlew ktlintCheck detekt cpdCheck --continue — BUILD SUCCESSFUL on this branch's diff.
• ./gradlew :app:assembleNoSentryDebug — APK built clean for install verification.
• Manual on-device sanity: not exercised here; the path is latent until a service-process consumer wires onTransportChanged. Behaviour change is purely classification source, observable only through the existing unit harness.

Implementer notes

• The activeNetwork read can race with the callback delivery (Android delivers NetworkCallback on its own ConnectivityThread, and activeNetwork is the OS's atomic snapshot). If the active route flipped between callback firing and our read, we just see the newer value, which is also correct; the next callback re-classifies. Same race the PR feat(InterfaceConfig): per-interface Wi-Fi/cellular network restriction #896 InterfaceTransportObserver fix accepts.
• The network: Network and networkCapabilities: NetworkCapabilities parameters on onCapabilitiesChanged stay — still feed the Log.v debug line and are required by the framework signature. Production now ignores networkCapabilities for classification but the parameter is still semantically there.
• The plan referenced an "Audit trail in the vault REJECTIONS.md for issue 894" filed by greptile-iterator — that file does not exist in the vault. Not load-bearing for this fix; flagging in case anyone hunts for it later.

🤖 Generated with Claude Code

[sentry]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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