refactor: centralize model factories and defaults (#2198)

include/stable-diffusion.h

@@ -94,6 +94,9 @@ enum prediction_t {
     SEFI_FLOW_PRED,
     MINIT2I_FLOW_PRED,
     SENSENOVA_U1_FLOW_PRED,
+    FLUX3_FLOW_PRED,
+    H3_AV_FLOW_PRED,
+    MING_IMAGE_FLOW_PRED,
     PREDICTION_COUNT
 };
 
@@ -487,8 +490,6 @@ SD_API int32_t sd_get_num_physical_cores();
 SD_API const char* sd_get_system_info();
 SD_API bool sd_ctx_supports_image_generation(const sd_ctx_t* sd_ctx);
 SD_API bool sd_ctx_supports_video_generation(const sd_ctx_t* sd_ctx);
-/** Returns whether the loaded model consumes ref_images as conditioning inputs. */
-SD_API bool sd_ctx_supports_ref_image_conditioning(const sd_ctx_t* sd_ctx);
 
 // ControlNet hot-swap APIs are not safe to call while generation is in flight.
 SD_API bool sd_ctx_load_control_net(sd_ctx_t* sd_ctx, const char* path);