otel: Documentation

[schloerke]

Goal: Document OTel features for users including API docs, user guide, and examples.

Tasks

• Add comprehensive docstrings to all public APIs:
  • shiny/otel/__init__.py
  • shiny/otel/_decorators.py (especially otel_collect)
• Create user guide documentation covering:
  • What is OpenTelemetry and why use it with Shiny
  • How to enable OTel in Shiny apps
  • Collection levels and what each captures
  • Configuration via environment variables
  • Programmatic control with context managers
  • Best practices for production use
  • Integration with observability backends (Jaeger, Zipkin, OTLP)
• Create example Shiny app demonstrating:
  • Basic setup with in-memory exporter
  • Console exporter for debugging
  • Integration with Jaeger or other backend
  • Using otel_collect to exclude sensitive operations
  • Viewing traces in Jaeger UI

Acceptance Criteria

• All public APIs have comprehensive docstrings with examples
• User guide covers common use cases and configuration
• At least one example app demonstrates end-to-end integration
• Documentation explains all 5 collection levels
• Documentation shows how to integrate with popular observability platforms

Files to Modify

• shiny/otel/__init__.py
• shiny/otel/_decorators.py

Files to Create

• User guide documentation page
• Example application(s) in examples/ or docs/examples/