[microsoft/vscode] Copilot chat OTel child spans are missing tool definitions

### ROOT CAUSE The issue arises because child spans (representing tool calls) in Copilot chat operations are not inheriting tool definition attributes from their parent spans. In OpenTelemetry, child spans inherit core trace context (trace ID, span ID) but not arbitrary attributes unless explicitly propagated. The tool definitions (likely metadata or attributes) are only set on parent spans (e.g., chat messages) and not inherited by child spans (tool calls). This results in missing tool definitions in the Aspire dashboard for some spans. ### CODE FIX To ensure tool definitions are included in child spans, explicitly propagate the tool definition attribute from parent to child spans. Modify the code that creates child spans to include the tool definition attribute. **Example Fix (pseudo-code):** ```typescript // When creating a child span for a tool call const childSpan = tracer.startSpan('tool_call', { // ... other options ... attributes: { 'tool.definition': parentSpan.getAttribute('tool.definition') || '{}' } }); ``` **Changes:** 1. **Parent Span:** Ensure the tool definition is stored as an attribute on the parent span (e.g., chat message span). 2. **Child Span:** When creating the child span (tool call), explicitly copy the `tool.definition` attribute from the parent. This ensures tool definitions are consistently included in all spans, resolving the discrepancy in the Aspire dashboard.