fix(use-case-compiler): compile questions from MCs, not hardcoded

Changes the compile flow to always query Master Controls from DB first:
1. doc_check_controls → Mode A (deterministic)
2. LLM generation via Ollama/Claude → Mode B
3. Derive from MC name → fallback
4. Template hardcoded questions → absolute fallback

Previously, templates with pre-defined questions just returned those
without ever hitting the DB. Now MC-compiled questions take priority
and template questions fill gaps for uncovered topics.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ai-compliance-sdk/internal/api/handlers/usecase_handler.go

@@ -16,17 +16,16 @@ type UseCaseHandler struct {
 	store       *usecase.Store
 	compiler    *usecase.Compiler
 	gapDetector *usecase.GapDetector
-	llmGen      *usecase.LLMQuestionGenerator
 }
 
 // NewUseCaseHandler creates a new UseCaseHandler.
 func NewUseCaseHandler(pool *pgxpool.Pool, registry *llm.ProviderRegistry) *UseCaseHandler {
 	store := usecase.NewStore(pool)
+	llmGen := usecase.NewLLMQuestionGenerator(registry)
 	return &UseCaseHandler{
 		store:       store,
-		compiler:    usecase.NewCompiler(store),
+		compiler:    usecase.NewCompiler(store, llmGen),
 		gapDetector: usecase.NewGapDetector(store),
-		llmGen:      usecase.NewLLMQuestionGenerator(registry),
 	}
 }
 
@@ -59,12 +58,11 @@ func (h *UseCaseHandler) GetTemplate(c *gin.Context) {
 
 // Compile generates questions from MC filters ad-hoc.
 // POST /sdk/v1/use-case/compile
-// Optional: "mode": "llm" to use LLM-based generation
+// Uses the full pipeline: doc_check → LLM → deterministic fallback
 func (h *UseCaseHandler) Compile(c *gin.Context) {
 	var req struct {
 		MCFilters   []string `json:"mc_filters" binding:"required"`
 		Regulations []string `json:"regulations"`
-		Mode        string   `json:"mode"` // "deterministic" (default) or "llm"
 	}
 	if err := c.ShouldBindJSON(&req); err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
@@ -77,29 +75,13 @@ func (h *UseCaseHandler) Compile(c *gin.Context) {
 		Regulations: req.Regulations,
 	}
 
-	if req.Mode == "llm" && h.llmGen != nil {
-		// Fetch MCs first, then generate via LLM
-		mcs, err := h.store.FetchMCsByFilters(req.MCFilters)
-		if err != nil {
-			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
-			return
-		}
-		questions, err := h.llmGen.GenerateQuestions(mcs, req.Regulations)
-		if err != nil {
-			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
-			return
-		}
-		c.JSON(http.StatusOK, gin.H{"questions": questions, "total": len(questions), "mode": "llm"})
-		return
-	}
-
 	questions, err := h.compiler.Compile(tmpl)
 	if err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 		return
 	}
 
-	c.JSON(http.StatusOK, gin.H{"questions": questions, "total": len(questions), "mode": "deterministic"})
+	c.JSON(http.StatusOK, gin.H{"questions": questions, "total": len(questions)})
 }
 
 // CreateAudit starts a new audit from a template.