Track 4: OTel Surface (metrics/traces/export)

[pikaxinge]

Context

Depends on Track 0 (event backbone). Can run in parallel with Track 3.

Scope

Track 4: OTel Surface

• T4.1 Metrics mapping
• T4.2 Trace mapping
• T4.3 Export pipeline (async, retry/backoff)

File Anchors

• extensions/diagnostics_otel/metrics.py (new) or snapagent/observability/otel_metrics.py
• extensions/diagnostics_otel/tracing.py (new)
• extensions/diagnostics_otel/service.py (new)

Acceptance Criteria

• Key metrics/traces are exported via OTLP
• Export failures do not block main runtime
• Config supports enable/disable and endpoint settings