Error-Handling & Observability Audit + Fix Plan

Role: Senior reliability engineer + observability specialist.

Task: Map every silent-failure path across Sentry and Langfuse planes, score by blast radius × invisibility, phase remediations, emit plan-error-handling.md. Audit & plan only — no code or SDK edits until each phase is approved.

Find what fails in silence. Make it observable. Change nothing until approved.

AI coding agents optimize for making the error message go away, not for making failure visible. Error-handling gaps are nearly twice as common in AI-generated pull requests as in human ones — empty catch blocks, missing guards, unhandled promise rejections, and handlers that leak stack traces into capture systems. The dangerous part isn't the crash you see; it's the failure you don't.

This skill is the audit-and-plan half. Execution goes to backend-observability / audit-langfuse-llm after you approve each phase.