Document internal component boundaries

docs/internal/prompt-input.md

@@ -1,54 +1,64 @@
 # Prompt Input Internals
 
-This document describes the implemented prompt input package boundary.
+This document describes prompt input data package construction.
 
 ## Purpose
 
-`internal/promptinput` converts a structured briefing package into the
-`data_package` JSON file passed to `scriptorium` prompts.
+`internal/promptinput` converts a structured briefing package and optional
+Recent Changes into the `data_package` JSON passed to Scriptorium prompts.
 
-## Inputs and Outputs
+## Inputs And Outputs
 
-Input:
+Inputs:
 
-- `briefing.Package` containing Daily-family, 3-Day Outlook, Weekend Outlook,
-  or Storm Report content
+- `briefing.Package`
+- optional `[]changes.Change`
 
-Output:
+Outputs:
 
-- `promptinput.Package` JSON with report metadata, briefing content, source
-  warnings, RunID, and a Recent Changes section.
+- `promptinput.Package` containing schema version, RunID, report metadata,
+  briefing content, Recent Changes, and source warnings
+- optional JSON file written by `promptinput.Save`
 
 ## Boundaries
 
-- This package owns the prompt input schema and required-field validation.
-- It does not fetch weather data, compute forecast summaries, compare prior
-  snapshots, or invoke `scriptorium`.
+- This package owns the prompt input schema and validation.
+- It does not fetch weather data, derive forecast summaries, find prior
+  snapshots, compare changes, or invoke Scriptorium.
 
-## Behavior
+## Config Fields Used
 
-- `promptinput.Build` copies report metadata from the briefing package.
-- `promptinput.Validate` rejects missing or inconsistent required fields before
-  render preflight.
-- `promptinput.Save` writes JSON atomically where practical.
-- Recent Changes is present as an `items` list. It is empty when no prior
-  comparable snapshot exists or no meaningful changes are detected.
+None directly. Config-derived values are already present in briefing metadata
+before this package runs.
+
+## External Adapters Used
+
+None.
+
+## State Or Manifest Behavior
+
+`promptinput.Save` writes JSON atomically. Managed workspace paths are owned by
+`internal/state`.
+
+## Skip And Resume Behavior
+
+None. Recent Changes is always present as an `items` list and may be empty.
 
 ## Failure Behavior
 
-Validation errors name the missing or inconsistent field. Save failures include
-the filesystem operation and path context.
+Validation fails before render preflight when required top-level or briefing
+metadata fields are missing or inconsistent, or when no report content is
+present. Save failures include filesystem operation and path context.
 
 ## Tests
 
 Inspect:
 
 - `internal/promptinput/package_test.go`
-- `internal/changes/daily_test.go`
 - `internal/app/app_test.go`
 
 ## Invariants
 
-- Prompt input data remains structured JSON.
+- Scriptorium receives structured `data_package` JSON.
 - Briefing metadata and top-level report metadata must agree.
-- Recent Changes is not inferred from rendered report text.
+- Recent Changes are not inferred from rendered report text.