feat: allow attach span context to logs

[abelonogov-ld]

Summary

Adds optional SpanContext parameter to recordLog so log records can be correlated with traces even when OTel context propagation is lost (e.g. detached threads, cross-process boundaries, .NET MAUI bridge).

Changes

SDK (observability-android)

• Split Observe into MetricsApi, LogsApi, TracesApi — Observe now composes all three via interface inheritance. This enables bridge layers to depend on narrower contracts.
• LogsApi.recordLog gains spanContext: SpanContext? — the old 3-arg signature is preserved as an extension function for backward compatibility.
• LogRecordEmitter — new shared extension Logger.emitLog(...) that attaches SpanContext to OTel log records via Context.root().with(Span.wrap(...)). Used by both ObservabilityService and KotlinLogger.
• KotlinLogger — new bridge-layer wrapper that accepts raw traceId/spanId strings (for .NET MAUI interop), reconstructs SpanContext, and routes through either the internal OTel logger or the level-gated LogsApi.
• LDObserveBridge.getKotlinLogger() — exposes KotlinLogger to bridge consumers.
• ObservabilityService.getLogger() — exposes the raw OTel Logger instance.

E2E app

• ViewModel.triggerLogWithContext() — demonstrates capturing SpanContext on the originating thread, then emitting a log from a detached Thread where automatic context propagation is lost.
• MainActivity — adds "Log with Context" button next to "Trigger Log".

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Note

Medium Risk
Changes the recordLog API surface to accept an optional SpanContext, which can impact downstream implementers/callers and affects trace-log correlation behavior. New bridge logger paths and context-setting logic could introduce subtle correlation or gating regressions if misused.

Overview
Adds optional trace correlation to logs by extending recordLog to accept a SpanContext? and updating LDObserve/ObservabilityService to propagate it.

Introduces shared OTel log emission helper (emitLog) plus a new bridge-facing KotlinLogger exposed via LDObserveBridge.getKotlinLogger() to allow non-Kotlin layers to record logs with explicit trace/span IDs. The e2e app UI and ViewModel add a demo action that records a log from a detached thread using a captured span context.

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