Centralize generated text template catalog

docs/internal/generatedtext.md

@@ -7,7 +7,9 @@ This document describes structured generated-text handling in
 
 `internal/generatedtext` validates structured text returned for
 generated-text-template reports and builds curated render contexts for
-templates. The implemented contracts are Tomorrow Report and Hourly Report.
+templates. It also owns the generated-text catalog that connects report
+definitions to validators, render-context builders, schema assets, and template
+assets. The implemented contracts are Tomorrow Report and Hourly Report.
 
 ## Inputs And Outputs
 
@@ -25,6 +27,8 @@ Outputs:
 - normalized stable JSON for validated generated text
 - typed `TomorrowRenderContext` values for `internal/reporttemplate`
 - typed `HourlyRenderContext` values for `internal/reporttemplate`
+- generated-text catalog handlers for report definitions that use
+  `generated_text_template`
 
 The hourly generated text JSON accepts:
 
@@ -60,10 +64,12 @@ JSON when blank.
 ## Boundaries
 
 - This package owns typed generated-text validation and render-context shaping.
+- It owns generated-text catalog lookup for schema/template combinations.
 - It uses typed module snapshot decoding through `module.StanzaValue`.
 - It does not invoke Scriptorium, write state artifacts, choose report
-  definitions, compare snapshots, or render templates directly in production
-  workflows.
+  definitions, compare snapshots, or own embedded template/schema files.
+- It renders through `internal/reporttemplate`; embedded asset lookup remains
+  in `internal/reporttemplate`.
 - It does not use a Go JSON Schema dependency; schema enforcement in Go is
   limited to typed JSON decoding, unknown-field rejection, and required-field
   checks.
@@ -77,6 +83,8 @@ JSON when blank.
 - Missing optional render-context stanzas become nil module pointers.
 - Invalid render metadata, including missing timezone, missing generated time,
   or invalid valid period, fails before template rendering.
+- Unsupported generated-text schema IDs, template IDs, or schema/template
+  combinations fail during catalog lookup with report ID context.
 
 ## Tests
 
@@ -84,11 +92,14 @@ Inspect:
 
 - `internal/generatedtext/hourly_test.go`
 - `internal/generatedtext/tomorrow_test.go`
+- `internal/generatedtext/catalog_test.go`
 - `internal/generatedtext/render_context_test.go`
 
 ## Invariants
 
 - Render contexts are curated structs, not raw prompt-input packages.
 - Required generated text is normalized before downstream artifact storage.
+- Generated-text-template reports must have one catalog entry matching their
+  report definition schema and template IDs.
 - Missing optional weather narrative stanzas produce empty or fallback render
   context fields rather than forcing raw module data into templates.