Add initial implementation of comfyui_api_sdk with API models and examples

example/example.dart

@@ -0,0 +1,94 @@
+import 'dart:io';
+import 'package:comfyui_api_sdk/comfyui_api_sdk.dart';
+
+void main() async {
+  // Create the API client
+  final api = ComfyUiApi(host: 'http://mennos-server:7860');
+
+  // Connect to the WebSocket for progress updates
+  await api.connectWebSocket();
+
+  // Listen for progress updates
+  api.progressUpdates.listen((update) {
+    print('Progress update: $update');
+  });
+
+  // Get available checkpoints
+  final checkpoints = await api.getCheckpoints();
+  print('Available checkpoints: ${checkpoints.keys.join(', ')}');
+
+  // Get queue status
+  final queue = await api.getQueue();
+  print('Queue status: $queue');
+
+  // Submit a basic text-to-image prompt
+  final promptWorkflow = {
+    "prompt": {
+      "3": {
+        "inputs": {
+          "seed": 123456789,
+          "steps": 20,
+          "cfg": 7,
+          "sampler_name": "euler_ancestral",
+          "scheduler": "normal",
+          "denoise": 1,
+          "model": ["4", 0],
+          "positive": ["6", 0],
+          "negative": ["7", 0],
+          "latent_image": ["5", 0]
+        },
+        "class_type": "KSampler"
+      },
+      "4": {
+        "inputs": {"ckpt_name": "dreamshaper_8.safetensors"},
+        "class_type": "CheckpointLoaderSimple"
+      },
+      "5": {
+        "inputs": {"width": 512, "height": 512, "batch_size": 1},
+        "class_type": "EmptyLatentImage"
+      },
+      "6": {
+        "inputs": {
+          "text": "a beautiful landscape with mountains and a lake",
+          "clip": ["4", 1]
+        },
+        "class_type": "CLIPTextEncode"
+      },
+      "7": {
+        "inputs": {
+          "text": "ugly, blurry, low quality",
+          "clip": ["4", 1]
+        },
+        "class_type": "CLIPTextEncode"
+      },
+      "8": {
+        "inputs": {
+          "samples": ["3", 0],
+          "vae": ["4", 2]
+        },
+        "class_type": "VAEDecode"
+      },
+      "9": {
+        "inputs": {
+          "filename_prefix": "ComfyUI",
+          "images": ["8", 0]
+        },
+        "class_type": "SaveImage"
+      }
+    },
+    "client_id": api.clientId
+  };
+
+  try {
+    final result = await api.submitPrompt(promptWorkflow);
+    print('Prompt submitted: $result');
+  } catch (e) {
+    print('Error submitting prompt: $e');
+  }
+
+  // Wait for some time to receive WebSocket messages
+  await Future.delayed(Duration(seconds: 60));
+
+  // Clean up
+  api.dispose();
+}