feat: Event Enrichment and Queueing, MetaRouterAnalyticsClient base class

[choudlet]

This branch implements the event queuing and enrichment foundation for the MetaRouter Android SDK. This is a critical
middleware layer that sits between event tracking calls and the networking layer (to be implemented in a future PR).

Key Components Added

1. MetaRouterAnalyticsClient (MetaRouterAnalyticsClient.kt)

• Main SDK client with full lifecycle management (IDLE → INITIALIZING → READY → RESETTING)
• Implements all core event tracking methods: track(), identify(), group(), screen(), page(), alias()
• Uses a Channel-based architecture (similar to Swift actors) to serialize event enrichment and provide natural
  backpressure
• Channel capacity set to maxQueueEvents / 2 for burst handling
• Thread-safe operations with AtomicReference for lifecycle state
• Identity management: advertising ID support with context cache invalidation
• Debug methods: getDebugInfo(), enableDebugLogging()

2. EventEnrichmentService (enrichment/EventEnrichmentService.kt)

• Enriches raw events with identity (anonymousId, userId, groupId)
• Adds device context (device, app, OS, screen, network, library, locale, timezone)
• Generates unique messageIds in format {epochMs}-{uuid}
• Formats timestamps in ISO 8601 UTC format
• Includes advertising ID in device context when available

3. EventQueue (queue/EventQueue.kt)

• Thread-safe FIFO queue with ReadWriteLock
• Configurable capacity with overflow protection (drops oldest events)
• Support for bulk drain operations
• Requeue capability for retry scenarios (adds to front)
• Debug statistics (size, capacity, utilization %)

4. Comprehensive Test Suite (MetaRouterAnalyticsClientTest.kt)

• 30+ unit tests covering all major scenarios
• Uses MockK for Android context mocking
• Tests: initialization, event tracking, identity management, lifecycle, error handling, concurrency, queue overflow

5. Updated Dependencies (build.gradle.kts)

• Added MockK testing framework (v1.13.9)
• Added MockK Android support

[github-actions]

Test Results

 28 files  + 4   28 suites  +4   36s ⏱️ +8s
187 tests  - 16  187 ✅  - 16  0 💤 ±0  0 ❌ ±0 
374 runs   - 32  374 ✅  - 32  0 💤 ±0  0 ❌ ±0 

Results for commit 6560d6e. ± Comparison against base commit 3265beb.

This pull request removes 93 and adds 77 tests. Note that renamed tests count towards both.

com.metarouter.analytics.context.DeviceContextProviderTest ‑ advertising ID with special characters is preserved
com.metarouter.analytics.context.DeviceContextProviderTest ‑ caching returns same context instance for same advertising ID
com.metarouter.analytics.context.DeviceContextProviderTest ‑ caching returns same context instance when no advertising ID
com.metarouter.analytics.context.DeviceContextProviderTest ‑ changing advertising ID invalidates cache and returns new context
com.metarouter.analytics.context.DeviceContextProviderTest ‑ clearCache invalidates cached context
com.metarouter.analytics.context.DeviceContextProviderTest ‑ concurrent cache clears and gets are safe
com.metarouter.analytics.context.DeviceContextProviderTest ‑ context with advertising ID then without uses cache correctly
com.metarouter.analytics.context.DeviceContextProviderTest ‑ device context excludes advertising ID when not provided
com.metarouter.analytics.context.DeviceContextProviderTest ‑ device context includes advertising ID when provided
com.metarouter.analytics.context.DeviceContextProviderTest ‑ empty string advertising ID is treated as present
…

com.metarouter.analytics.MetaRouterAnalyticsClientTest ‑ alias updates userId and enqueues event
com.metarouter.analytics.MetaRouterAnalyticsClientTest ‑ alias with empty userId logs warning and does not enqueue
com.metarouter.analytics.MetaRouterAnalyticsClientTest ‑ all event types can be created and queued
com.metarouter.analytics.MetaRouterAnalyticsClientTest ‑ enableDebugLogging enables debug mode
com.metarouter.analytics.MetaRouterAnalyticsClientTest ‑ events cannot be enqueued after reset
com.metarouter.analytics.MetaRouterAnalyticsClientTest ‑ events include all required fields per spec
com.metarouter.analytics.MetaRouterAnalyticsClientTest ‑ flush is a no-op stub
com.metarouter.analytics.MetaRouterAnalyticsClientTest ‑ getDebugInfo masks writeKey correctly
com.metarouter.analytics.MetaRouterAnalyticsClientTest ‑ getDebugInfo returns complete information
com.metarouter.analytics.MetaRouterAnalyticsClientTest ‑ group updates groupId and enqueues event
…

♻️ This comment has been updated with latest results.