Document Tomorrow generated-text workflow

docs/internal/reporttemplate.md

@@ -6,8 +6,8 @@ in `internal/reporttemplate`.
 ## Purpose
 
 `internal/reporttemplate` owns repository-native report templates and companion
-GeneratedText JSON schemas. The first implemented template contract is the
-Hourly Report.
+GeneratedText JSON schemas. The implemented template contracts are Tomorrow
+Report and Hourly Report.
 
 The package embeds assets from:
 
@@ -27,8 +27,9 @@ Outputs:
 - GeneratedText schema bytes for prompt/schema configuration
 - rendered Markdown bytes for app orchestration to persist
 
-The implemented template ID is `hourly`. The implemented schema ID is also
-`hourly`, backed by `hourly.generated_text.schema.json`.
+The implemented template IDs are `tomorrow` and `hourly`. The implemented
+schema IDs are also `tomorrow` and `hourly`, backed by
+`tomorrow.generated_text.schema.json` and `hourly.generated_text.schema.json`.
 
 ## Boundaries
 
@@ -41,31 +42,37 @@ GeneratedText validation is owned by `internal/generatedtext`. App
 orchestration decides which template and schema IDs apply to a report through
 `internal/report` definitions.
 
-## Template Contract
+## Template Contracts
 
-Hourly rendering uses a typed render context with:
+Tomorrow and Hourly rendering use typed render contexts with:
 
 - report metadata labels such as title, location, valid period, and generation
   time
-- validated hourly GeneratedText prose slots
+- validated GeneratedText prose slots
 - deterministic labels derived from module outputs, including current
   conditions, hourly forecast rows, precipitation timing, alerts, SPC outlooks,
   forecast discussion, SPC discussion, and weather story
 
+Tomorrow additionally exposes forecast-date labels, ordered daypart forecast
+rows, daily/daypart summaries, tomorrow planning facts, and a multi-paragraph
+forecast discussion generated-text slot. The ordered daypart slice is built in
+Go so templates do not range over maps.
+
 Templates use `text/template` with `missingkey=error`, so missing context fields
 fail rendering instead of producing incomplete Markdown.
 
 ## Schema Contract
 
-The hourly GeneratedText schema describes the structured prose Scriptorium is
-expected to write for the prompt. It requires:
+The GeneratedText schemas describe the structured prose Scriptorium is expected
+to write for each generated-text prompt. Hourly requires:
 
 - `summary`
 - `forecast_discussion`
 
-It allows optional `precipitation_timing` and `confidence`, and rejects
-additional properties. Weather truth remains in module outputs; GeneratedText is
-limited to prose slots consumed by the template.
+Tomorrow requires `summary` and a nonempty `forecast_discussion` array. Both
+schemas allow optional `precipitation_timing` and `confidence`, and reject
+additional properties. Weather truth remains in module outputs; GeneratedText
+is limited to prose slots consumed by the template.
 
 ## Failure Behavior