Add OpenTelemetry integration for Stories with hooks-based tracing

[mom1]

Description

Implement OpenTelemetry integration for the Stories framework using hooks to enable distributed tracing capabilities.

Requirements

• Story Run Tracing: Each story execution should create a separate root span
• Step-level Tracing: Each step within a story should create a nested span as a child of the story span
• Hook-based Implementation: Use hooks to instrument story lifecycle events without requiring invasive code changes
• Context Propagation: Ensure proper trace context propagation across story runs and steps
• Configurable: Allow users to enable/disable tracing and configure OpenTelemetry exporters

Implementation Details

Hook Integration

• on_story_start: Create root span for story execution
• on_story_end: End root span, record final status
• on_step_start: Create child span for step execution
• on_step_end: End step span, record step result

Span Attributes

• Story span: story_id, story_name, started_at, ended_at, status
• Step span: step_id, step_name, step_order, started_at, ended_at, status

Configuration

• Support for standard OpenTelemetry exporters (OTLP, Jaeger, Zipkin, etc.)
• Configurable span attributes and naming conventions
• Optional: trace sampling configuration

Testing

• Unit tests for hook execution
• Integration tests with OpenTelemetry SDK
• Example demonstrating tracing with Jaeger backend