Add support for Colmi R02 ring - #6

Summary

This PR turns PulseLoop from a single-ring app into a device-agnostic wearable platform and adds full Colmi R02 (Yawell) support alongside the existing jring. The changes made in the PR will also help in adding support for new wearables in the future. Most of the Colmi rings use the same hardware as the Colmi R02, so this PR should make PulseLoop fully compatible with R02/R06/R10 and partially compatible with other.

The information protocol for Colmi R02 was gathered from tahnok's colmi_r02_client and GadgetBridge.

Changes

• Platform core (Wearables/): WearableCoordinator, WearableDriver, RingSyncEngine, WearableCapability, RingDeviceType. - - RingBLEClient is now driver-agnostic (coordinator registry, per-connection driver, multi-notify, framing seam, Forget); RingSyncCoordinator is a façade.
• jring refactor: moved behind JringCoordinator/JringDriver/JringSyncEngine.
• Colmi driver: ColmiProtocol (UUIDs/opcodes/16-byte checksum packet), ColmiEncoder, ColmiDecoder, ColmiDriver (dual notify channels + big-data reassembly), ColmiSyncEngine (7-stage history machine + realtime-HR keepalive).
• New metrics: HRV, stress, body temperature, REM sleep MeasurementKind/SleepStage/MeasurementSource/events/persistence; Device.deviceType/capabilities (additive SwiftData migration).
• Capability-driven UI: bespoke Vitals cards: stress zone gauge, HRV trend band, temperature range chart, gated by device capability (jring auto-hides what it lacks); REM in the hypnogram; clean device card with last-synced + Forget; device-neutral onboarding; Coach reads the new metrics.
• Hidden diagnostics: removed visible Debug button / Settings entries / Vitals "CONFIDENCE" line; DebugView + raw-packet capture are now #if DEBUG-only; new structured WearableLog store + DiagnosticsSubscriber + Export diagnostics (.json) in Settings (about)

Testing

• Debug and Release builds: Passing
• New ColmiDecoderTests (checksum, big-data reassembly across split packets, battery, manual/realtime HR, live activity, sleep REM/awake, temp, SpO₂) and CapabilityGatingTests: Passing
• Touched existing suites (RingDecoderTests, EventBridgeTests, DebugRepositoryTests, MetricsServiceTodayTests) — passing, confirming no jring regression.

TO DO

• On device testing with the ring.