fix: preserve existing template when adding parameters

src/models/Config.tsx

@@ -97,29 +97,48 @@ export class Config {
    * Updates template by adding placeholders for environment params
    */
   public updateTemplateFromEnv(env: Env): void {
-    let templateObj: Record<string, string> = {};
+    // If template is empty, initialize with empty object
+    if (!this.template.content || !this.template.content.trim()) {
+      this.template = new ConfigTemplate('{}');
+    }
 
     // Try to parse existing template
+    let templateObj: Record<string, any> = {};
+    let hasExistingContent = false;
+    
     try {
       if (this.template.content.trim()) {
         templateObj = JSON.parse(this.template.content);
+        hasExistingContent = Object.keys(templateObj).length > 0;
       }
     } catch {
-      // Start fresh if invalid JSON
+      // If invalid JSON, preserve the raw content and don't modify
+      return;
     }
 
     // Add placeholders for params that don't exist yet
+    let hasChanges = false;
     for (const param of env.params) {
       if (param.name && param.name.trim()) {
-        const placeholder = `@${param.name}@`;
+        const paramName = param.name.trim();
+        const placeholder = `@${paramName}@`;
+        const templateKey = `!!! ${paramName}`;
 
+        // Check if placeholder exists anywhere in template
         if (!this.template.content.includes(placeholder)) {
-          templateObj[`!!! ${param.name}`] = placeholder;
+          // Only add if not already in templateObj
+          if (!templateObj[templateKey]) {
+            templateObj[templateKey] = placeholder;
+            hasChanges = true;
+          }
         }
       }
     }
 
-    this.template = new ConfigTemplate(JSON.stringify(templateObj, null, 4));
+    // Only update if there are actual changes
+    if (hasChanges || !hasExistingContent) {
+      this.template = new ConfigTemplate(JSON.stringify(templateObj, null, 4));
+    }
   }
 
   /**