feat: add GET /api/provision/images endpoint

- Add handleGetOsImages handler in provision.ts
- Add getOsImages method in ProvisioningService
- Add route in index.ts
- Returns key, name, family, is_default for each OS image

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/handlers/provision.ts

@@ -338,6 +338,38 @@ export async function handleGetBalance(
   }
 }
 
+/**
+ * GET /api/provision/images
+ * Get available OS images
+ */
+export async function handleGetOsImages(
+  env: Env,
+  corsHeaders: Record<string, string>
+): Promise<Response> {
+  try {
+    const provisioningService = new ProvisioningService(
+      env,
+      env.DB,
+      env.USER_DB
+    );
+
+    const images = await provisioningService.getOsImages();
+
+    // Return simplified image list for API consumers
+    const response = images.map((img) => ({
+      key: img.key,
+      name: img.name,
+      family: img.family,
+      is_default: img.is_default === 1,
+    }));
+
+    return createSuccessResponse({ images: response }, 200, corsHeaders);
+  } catch (error) {
+    console.error('[handleGetOsImages] Error:', error);
+    return createErrorResponse('Internal server error', 500, undefined, corsHeaders);
+  }
+}
+
 /**
  * Map error codes to HTTP status codes
  */