Capture prompt requirement metadata and templates

internal/configuration/load.go

@@ -54,10 +54,10 @@ type promptConfig struct {
 }
 
 type promptInputConfig struct {
-	Name        string `yaml:"name"`
-	Required    bool   `yaml:"required"`
-	ContentType string `yaml:"content_type"`
-	Description string `yaml:"description"`
+	Name        string  `yaml:"name"`
+	Required    bool    `yaml:"required"`
+	ContentType *string `yaml:"content_type"`
+	Description *string `yaml:"description"`
 }
 
 type promptMessageConfig struct {
@@ -93,6 +93,7 @@ type loaded struct {
 	result          *configkit.Result[document]
 	backends        map[string]map[string]fieldState
 	profiles        map[string]map[string]fieldState
+	promptMetadata  map[string]map[string][]promptInputPresence
 	prompts         map[string]map[string]*promptEntry
 	ambiguous       map[string]bool
 	registry        *backend.Registry
@@ -112,8 +113,9 @@ func Load(main configkit.Input, underlays []configkit.Underlay) (*loaded, error)
 // load performs one ConfigKit lifecycle over the selected source tiers.
 func load(main configkit.Input, underlays []configkit.Underlay) (*loaded, error) {
 	state := &loaded{
-		backends: make(map[string]map[string]fieldState),
-		profiles: make(map[string]map[string]fieldState),
+		backends:       make(map[string]map[string]fieldState),
+		profiles:       make(map[string]map[string]fieldState),
+		promptMetadata: make(map[string]map[string][]promptInputPresence),
 	}
 	result, err := configkit.LoadLayered(main, configkit.LayeredOptions[document]{
 		Underlays: underlays,
@@ -122,6 +124,7 @@ func load(main configkit.Input, underlays []configkit.Underlay) (*loaded, error)
 			Resolve: func(config *document, resolution *configkit.Resolution) error {
 				captureFields(config.Backends, "backends", backendFields, resolution, state.backends)
 				captureFields(config.Profiles, "profiles", profileFields, resolution, state.profiles)
+				capturePromptMetadata(config.Prompts, resolution, state.promptMetadata)
 				resolveBackends(config.Backends, resolution)
 				resolveProfiles(config.Profiles, resolution)
 				resolvePrompts(config.Prompts, resolution)
@@ -143,6 +146,44 @@ func load(main configkit.Input, underlays []configkit.Underlay) (*loaded, error)
 	return state, nil
 }
 
+type promptInputPresence struct {
+	contentType fieldState
+	description fieldState
+}
+
+func capturePromptMetadata(prompts map[string]map[string]promptConfig, resolution *configkit.Resolution, destination map[string]map[string][]promptInputPresence) {
+	for _, id := range sortedKeys(prompts) {
+		if destination[id] == nil {
+			destination[id] = make(map[string][]promptInputPresence, len(prompts[id]))
+		}
+		for _, version := range sortedKeys(prompts[id]) {
+			inputs := prompts[id][version].Inputs
+			states := make([]promptInputPresence, len(inputs))
+			base := configkit.Keys("prompts", id, version, "inputs")
+			for index := range inputs {
+				path := base.Index(index)
+				states[index] = promptInputPresence{
+					contentType: captureFieldState(path.Key("content_type"), resolution),
+					description: captureFieldState(path.Key("description"), resolution),
+				}
+			}
+			destination[id][version] = states
+		}
+	}
+}
+
+func captureFieldState(path configkit.Path, resolution *configkit.Resolution) fieldState {
+	info, exists := resolution.InputInfo(path)
+	switch {
+	case !exists || !info.Explicit:
+		return fieldAbsent
+	case info.Null:
+		return fieldNull
+	default:
+		return fieldValue
+	}
+}
+
 func captureFields[T any](entries map[string]T, collection string, fields []string, resolution *configkit.Resolution, destination map[string]map[string]fieldState) {
 	for id := range entries {
 		states := make(map[string]fieldState, len(fields))