No configuration migration path for upgrades

**Severity:** Low
**Component:** Configuration
**Simulation:** SIM-L4-007
**Sprint:** 6

## Description
No migration system for configuration versions.

## Proposed Fix
Implement versioned config with migration scripts.

## Source
Imported from `.straymark/02-design/risk-analysis/BACKLOG-simulation-issues.md` on 2026-05-29.