feat(server): implement vid_gen async API and mode-aware capabilities (#1437)

examples/server/runtime.h

@@ -58,13 +58,32 @@ struct ImgGenJobRequest {
     }
 };
 
+struct VidGenJobRequest {
+    SDGenerationParams gen_params;
+    std::string output_format = "webm";
+    int output_compression    = 100;
+
+    sd_vid_gen_params_t to_sd_vid_gen_params_t() {
+        return gen_params.to_sd_vid_gen_params_t();
+    }
+};
+
 std::string base64_encode(const std::vector<uint8_t>& bytes);
 std::string normalize_output_format(std::string output_format);
+std::vector<std::string> supported_img_output_formats(bool allow_webp = true);
+std::vector<std::string> supported_vid_output_formats();
 bool assign_output_options(ImgGenJobRequest& request,
                            std::string output_format,
                            int output_compression,
                            bool allow_webp,
                            std::string& error_message);
+bool assign_output_options(VidGenJobRequest& request,
+                           std::string output_format,
+                           int output_compression,
+                           std::string& error_message);
+std::string video_mime_type(const std::string& output_format);
+bool runtime_supports_generation_mode(const ServerRuntime& runtime, SDMode mode);
+std::string unsupported_generation_mode_error(SDMode mode);
 void refresh_lora_cache(ServerRuntime& rt);
 std::string get_lora_full_path(ServerRuntime& rt, const std::string& path);
 int64_t unix_timestamp_now();