refactor(app): remove legacy view models and UI handlers

[Foxpace]

Removes the previous phone presentation model after responsibility moved into core, domain, and Compose layers.

What was added

• Removal of legacy repositories and activity-scoped view models.
• Removal of graph, text, sensor-view, and storage UI handlers.
• Removal of old sensor attribute and resource wrapper types.

How it works

MainViewModel now owns immutable presentation state and delegates work to domain use cases. Core repositories handle preferences and storage, sensor descriptors provide UI-ready metadata, and Compose recomposition replaces imperative graph, text, and view updates.

Stack position

Layer 26 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Superseded by #46, which targets master and shows the final current tree.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 The architecture work continues as stacked PRs #47 through #54; consolidated PR #46 is superseded.