fix: expose probe route fee

[pwltr]

Summary

• Expose routeFeeMsat in debug probe devtools responses.
• Include the route fee for both successful and failed probe outcomes.
• Enables e2e probe reports to consume the route fee already captured by the Android probe outcome path.

Testing

• Ran ./gradlew :app:compileMainnetDebugKotlin successfully.

[greptile-apps]

Greptile Summary

This PR exposes probe route fees through debug devtools responses. The main changes are:

• Adds nullable routeFeeMsat fields to successful and failed probe results.
• Copies the existing route fee from both probe outcome variants.

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.
• Both outcome variants preserve the existing ULong? type and null behavior.

Important Files Changed

Filename	Overview
app/src/debug/java/to/bitkit/dev/DevToolsProvider.kt	Adds the existing nullable probe route fee to both serialized devtools result variants.

_{Reviews (1): Last reviewed commit: "fix: expose probe route fee" | Re-trigger Greptile}