Add a new narrative forecast module and remove the unimplemented daily forecast stub

docs/internal/briefing.md

@@ -27,15 +27,14 @@ Outputs:
 - `ModuleDefinition` values with module ID, stanza name, option type,
   supported reports, fact requirements, missing-data behavior, and builder
 - `module.Output` values for source-oriented stanzas:
-  `metadata`, `current_conditions`, `alert_digest`,
+  `metadata`, `current_conditions`, `narrative_forecast`, `alert_digest`,
   `area_forecast_discussion`, and `weather_story`
 - `module.Output` values for derived stanzas:
   `derived_daily_summary`, `derived_daypart_summaries`, `precip_timing`,
   `outdoor_windows`, and `tomorrow_planning`
 
-The registry also contains accepted composition entries for modules that do not
-emit stanzas until a builder exists. App orchestration skips those entries when
-constructing snapshots.
+Every registered composition entry has a builder. Unknown or unimplemented
+module IDs fail validation instead of being skipped.
 
 ## Boundaries
 

docs/internal/module.md

@@ -31,6 +31,7 @@ The registry recognizes these IDs:
 
 - `metadata`
 - `current_conditions`
+- `narrative_forecast`
 - `derived_daily_summary`
 - `derived_daypart_summaries`
 - `precip_timing`

docs/internal/prompt-input.md

@@ -39,6 +39,7 @@ report:
 briefing:
   metadata: {}
   current_conditions: {}
+  narrative_forecast: {}
 recent_changes:
   items: []
 ```

docs/internal/weather-data.md

@@ -22,7 +22,6 @@ Outputs:
 - `weatherdata.Bundle` with observation, current conditions, hourly forecast,
   narrative forecast, active alerts, discussion, latest weather story, source
   records, and source warnings
-- stub source record for the daily forecast source slot
 - optional saved bundle JSON through app fetch helpers
 
 ## Boundaries
@@ -70,7 +69,7 @@ data is required and cannot be skipped.
 - HTTP errors, response read failures, and envelope decode failures include
   endpoint context.
 - Missing hourly data or hourly forecasts with no periods fail bundle fetch.
-- Optional and stub sources follow missing-source policy.
+- Optional sources follow missing-source policy.
 - Explicit `data: null` from `/alerts/active` produces an empty, non-missing
   alert run.