Add module contracts and registry validation

docs/internal/report-registry.md

@@ -23,6 +23,7 @@ Each report definition declares:
 - generated-report eligibility
 - prior-report compatibility list
 - morning or evening batch membership
+- default ordered module composition
 
 ## Implemented Reports
 
@@ -70,6 +71,7 @@ output path copying uses batch output names from report definitions.
 - State paths use `ArtifactGroup`.
 - Batch output copies use `BatchOutputName`.
 - Generation checks `Generated`.
+- Module composition defaults use `Modules`.
 - Prior lookup checks `CompatiblePriorIDs` and the comparison strategy.
 - RunIDs include the resolved report ID.
 
@@ -93,5 +95,5 @@ Inspect:
 - Daily Today and Daily Tomorrow both use `weather.daily_report`.
 - Valid periods are half-open intervals independent of rendered report text.
 - Artifact grouping, batch output filenames, generated-report eligibility,
-  comparison compatibility, and comparison strategy are declared by report
-  definition.
+  default module composition, comparison compatibility, and comparison strategy
+  are declared by report definition.