feat: Add debug print instrumentation.

[kinyoklion]

Summary

Adds debugPrint instrumentation and zone configuration for normal print.

Includes some additional refactoring to account for shutting down instrumentations.

How did you test this change?

Manual testing.

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Note

Adds configurable debugPrint/print instrumentation, introduces Observe/Otel shutdown and plugin registration, and updates example and exports accordingly.

• Instrumentation:
  • Add DebugPrintInstrumentation to capture debugPrint (configurable via new InstrumentationConfig and DebugPrintSetting).
  • Extend Instrumentation interface with dispose(); make LifecycleInstrumentation.dispose() idempotent.
  • Wire instrumentation into ObservabilityPlugin (new instrumentation param) and add dispose().
• Observe/Otel lifecycle:
  • Add Observe.shutdown() and plugin tracking; introduce registerPlugin(...).
  • Add Observe.zoneSpecification() to capture print.
  • Refactor OTEL setup into Otel class with setup()/shutdown().
• Config/Exports:
  • Extend ObservabilityConfig to include instrumentationConfig and export InstrumentationConfig/DebugPrintSetting.
• Example app:
  • Configure ObservabilityPlugin with InstrumentationConfig(debugPrint: DebugPrintSetting.always()).
  • Use zoneSpecification: Observe.zoneSpecification() and add buttons to trigger debugPrint/print.

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[kinyoklion]

bugbot review