refactor(ui): compose resources, domain layer

[jamesarich]

This pull request primarily migrates all string and resource management from the core:strings module to a new centralized core:resources module, and updates all relevant references and documentation throughout the codebase. Additionally, it introduces a new use case for device discovery and improves robustness for service initialization during testing.

Resource module migration and documentation updates:

• All code and documentation references to core:strings have been updated to core:resources, including import paths, Gradle dependencies, and module diagrams. This centralizes string, drawable, and other resource management in :core:resources and clarifies best practices for resource placement and usage. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]

New functionality:

• Added GetDiscoveredDevicesUseCase in app/src/main/java/com/geeksville/mesh/domain/usecase/, which aggregates BLE, USB, and TCP devices, as well as recent TCP connections, into a unified flow for device discovery in the app.

Codebase robustness and minor improvements:

• Improved MeshService startup logic to gracefully handle Hilt initialization errors during tests, preventing test failures due to premature service creation.
• Minor code formatting improvement in app/build.gradle.kts for variant application ID assignment.

Summary of most important changes:

Resource Management Migration

• All references to strings and resources have been moved from core:strings to core:resources, including imports, Gradle dependencies, and documentation. This centralizes global resources and clarifies modular boundaries for feature-specific assets. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]

New Device Discovery Use Case

• Introduced GetDiscoveredDevicesUseCase, which combines BLE, USB, TCP, and recent device discovery logic into a single flow for use in the app's device list.

Service Initialization Robustness

• Enhanced MeshService to catch and handle Hilt initialization errors during tests, improving reliability in CI and test environments.

Documentation and Diagram Updates

• Updated documentation (AGENTS.md, CONTRIBUTING.md, and module diagrams in app/README.md) to reflect the new resource module structure and best practices for resource management. [1] [2] [3] [4] [5]

Minor Code Quality Improvements

• Improved code formatting in app/build.gradle.kts for clarity and consistency.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 57 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (main@96adc70). Learn more about missing BASE report.
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...mesh/domain/usecase/GetDiscoveredDevicesUseCase.kt	0.00%	43 Missing ⚠️
...geeksville/mesh/ui/connections/ScannerViewModel.kt	0.00%	14 Missing ⚠️

Additional details and impacted files

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  Misses          ?     3334           
  Partials        ?      126           

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