Move prompts into embedded Markdown assets

internal/framework/proposal_generation/generate.go

@@ -55,6 +55,7 @@ type Request struct {
 	Config            *config.Config              `json:"-"`
 	Messages          []contracts.LLMMessage      `json:"messages"`
 	Model             string                      `json:"model,omitempty"`
+	PromptMetadata    map[string]any              `json:"prompt_metadata,omitempty"`
 	StageName         string                      `json:"stage_name,omitempty"`
 	StartIndex        int                         `json:"start_index"`
 	LLMClient         contracts.StructuredLLMClient
@@ -137,6 +138,9 @@ func GenerateCandidates(ctx context.Context, req Request) (Result, error) {
 		"start_index":        req.StartIndex,
 		"model":              model,
 	}
+	if len(req.PromptMetadata) > 0 {
+		requestMetadata["prompt_metadata"] = req.PromptMetadata
+	}
 	requestMetadata["response_schema"] = schemaMetadata(responseSchema)
 
 	if writer != nil {