feat: add audio type to API types and connection wiring

Add generateAudio to getNodeHandles() for connection validation, wire
audio handle type in connection drop menu, and add "audio" mediaType
to GenerateRequest/GenerateResponse API types.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/WorkflowCanvas.tsx

@@ -124,6 +124,8 @@ const getNodeHandles = (nodeType: string): { inputs: string[]; outputs: string[]
       return { inputs: ["image", "text"], outputs: ["video"] };
     case "generate3d":
       return { inputs: ["image", "text"], outputs: ["3d"] };
+    case "generateAudio":
+      return { inputs: ["text"], outputs: ["audio"] };
     case "llmGenerate":
       return { inputs: ["text", "image"], outputs: ["text"] };
     case "splitGrid":
@@ -810,7 +812,7 @@ export function WorkflowCanvas() {
           sourceHandleIdForNewNode = "image";
         }
       } else if (handleType === "text") {
-        if (nodeType === "nanoBanana" || nodeType === "generateVideo" || nodeType === "llmGenerate") {
+        if (nodeType === "nanoBanana" || nodeType === "generateVideo" || nodeType === "generateAudio" || nodeType === "llmGenerate") {
           targetHandleId = "text";
           // llmGenerate also has a text output
           if (nodeType === "llmGenerate") {
@@ -841,6 +843,10 @@ export function WorkflowCanvas() {
         if (nodeType === "audioInput") {
           // AudioInput outputs audio
           sourceHandleIdForNewNode = "audio";
+        } else if (nodeType === "generateAudio") {
+          // GenerateAudio outputs audio
+          sourceHandleIdForNewNode = "audio";
+          targetHandleId = "text";
         } else if (nodeType === "videoStitch") {
           // VideoStitch accepts audio
           targetHandleId = "audio";

src/types/api.ts

@@ -16,7 +16,7 @@ export interface GenerateRequest {
   resolution?: Resolution; // Only for Nano Banana Pro
   model?: ModelType;
   useGoogleSearch?: boolean; // Only for Nano Banana Pro
-  mediaType?: "image" | "video" | "3d"; // Indicates expected output type for provider routing
+  mediaType?: "image" | "video" | "3d" | "audio"; // Indicates expected output type for provider routing
 }
 
 export interface GenerateResponse {
@@ -24,8 +24,10 @@ export interface GenerateResponse {
   image?: string;
   video?: string;
   videoUrl?: string; // For large videos, return URL directly
+  audio?: string; // Base64 audio data
+  audioUrl?: string; // For large audio, return URL directly
   model3dUrl?: string; // For 3D models, return GLB URL directly
-  contentType?: "image" | "video" | "3d";
+  contentType?: "image" | "video" | "3d" | "audio";
   error?: string;
 }