refactor(sensorservice): modernize service runtime

[Foxpace]

Refactors the foreground measurement runtime around explicit configuration and session state.

What was added

• A MeasurementConfig model for service startup options.
• Updated service controller and foreground MeasurementService lifecycle handling.
• Notification updates driven by the new runtime state.
• Removal of the legacy MeasurementStates enum.

How it works

The controller builds a typed configuration and starts the service. MeasurementService uses that configuration to create measurements, updates the shared session store as the lifecycle changes, and keeps the foreground notification synchronized with the active recording state.

Stack position

Layer 6 of 31 in the SensorBox refactor stack. Review this PR against its configured base to see only this layer.

Validation

• Full stack: ./gradlew test — BUILD SUCCESSFUL (160 tasks)

[Foxpace]

Superseded by #46, which targets master and shows the final current tree. Closing this stacked layer so review stays on the consolidated diff; this PR remains available as history.

[Foxpace]

Stack restored at the author's request. This PR is again part of the original 31-layer refactor chain. The architecture work continues as stacked PRs #47 through #54; consolidated PR #46 is superseded.