feat: Enhanced tracing spans with retry and timing context

[joshrotenberg]

Description

Enhance existing tracing spans to include retry attempts and detailed timing breakdowns for better observability.

Requirements

• Add retry attempt number to spans
• Add retry reason (timeout, status code, etc.)
• Add cumulative retry delay
• Add request/response sizes
• Add cache hit/miss information (if applicable)
• Add rate limit information

Implementation Details

• Extend existing span attributes
• Use OpenTelemetry semantic conventions where applicable
• Structure span data for easy querying in observability tools
• Include correlation IDs for request tracking

Acceptance Criteria

• All retry attempts create child spans
• Retry spans include backoff duration
• Failed requests include error details in spans
• Spans can be correlated across service boundaries
• Span data is structured for analysis