Add module contracts and registry validation

docs/policy/development.md

@@ -20,6 +20,7 @@ Developers and LLM coding agents should use it with
   source warnings.
 - `internal/forecast`: deterministic forecast derivation.
 - `internal/facts`: collected and derived report fact contracts.
+- `internal/module`: module IDs, config items, output envelopes, and snapshots.
 - `internal/report`: report definitions, valid periods, batches, output names,
   and comparison declarations.
 - `internal/briefing`: report-specific briefing package builders.