feat: add diagnostic interview loop

internal/httpapi/handler.go

@@ -5,24 +5,27 @@ import (
 	"net/http"
 
 	"tutor/internal/config"
-	"tutor/internal/workflows"
+	"tutor/internal/interview"
 )
 
 type Handler struct {
-	cfg    config.Config
-	runner workflows.Runner
+	cfg        config.Config
+	diagnostic *interview.Service
 }
 
-func NewHandler(cfg config.Config, runner workflows.Runner) Handler {
+func NewHandler(cfg config.Config, diagnostic *interview.Service) Handler {
 	return Handler{
-		cfg:    cfg,
-		runner: runner,
+		cfg:        cfg,
+		diagnostic: diagnostic,
 	}
 }
 
 func (h Handler) Routes() http.Handler {
 	mux := http.NewServeMux()
 	mux.HandleFunc("GET /healthz", h.health)
+	mux.HandleFunc("POST /api/v1/diagnostic-sessions", h.createDiagnosticSession)
+	mux.HandleFunc("GET /api/v1/diagnostic-sessions/{id}", h.getDiagnosticSession)
+	mux.HandleFunc("POST /api/v1/diagnostic-sessions/{id}/answers", h.submitDiagnosticAnswer)
 	return mux
 }
 
@@ -45,3 +48,11 @@ func writeJSON(w http.ResponseWriter, status int, value any) {
 	w.WriteHeader(status)
 	_ = json.NewEncoder(w).Encode(value)
 }
+
+func writeError(w http.ResponseWriter, status int, message string) {
+	writeJSON(w, status, errorResponse{Error: message})
+}
+
+type errorResponse struct {
+	Error string `json:"error"`
+}