Epic: Error Handling & Observability

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Overview

Improve error handling with a custom exception hierarchy and add observability features (correlation IDs, PII-safe logging).

Phase 1 — Exception hierarchy

• quality(errors): implement custom exception hierarchy #99 — quality(errors): implement custom exception hierarchy

Phase 2 — Observability

• quality(logging): add correlation IDs to request logging #86 — quality(logging): add correlation IDs to request logging
• security(logging): prevent PII leakage in LogsActivity trait #87 — security(logging): prevent PII leakage in LogsActivity trait

Previously Created (existing)

• Error Handling: ResilientSession redirect loop potential #28

Exit Criteria

All generic exceptions replaced with domain-specific ones. All requests carry correlation IDs. No PII in logs.