feat: resolve app template env placeholders

ts/classes/services.ts

@@ -112,9 +112,15 @@ export class OneboxServicesManager {
 
       // Merge platform env vars with user-specified env vars (user vars take precedence)
       const mergedEnvVars = { ...platformEnvVars, ...(options.envVars || {}) };
+      this.resolveEnvVarTemplates(mergedEnvVars, {
+        ...platformEnvVars,
+        SERVICE_NAME: options.name,
+        SERVICE_DOMAIN: options.domain || '',
+        SERVICE_PORT: String(options.port),
+      });
 
-      // Update service with merged env vars
-      if (Object.keys(platformEnvVars).length > 0) {
+      // Update service with merged and resolved env vars.
+      if (Object.keys(mergedEnvVars).length > 0) {
         this.database.updateService(service.id!, { envVars: mergedEnvVars });
       }
 
@@ -697,6 +703,29 @@ export class OneboxServicesManager {
     }
   }
 
+  private resolveEnvVarTemplates(
+    envVarsArg: Record<string, string>,
+    valuesArg: Record<string, string>,
+  ): void {
+    for (const [key, value] of Object.entries(envVarsArg)) {
+      const missingValues = new Set<string>();
+      const resolvedValue = value.replace(/\$\{([A-Z0-9_]+)\}/g, (match, placeholderName) => {
+        const replacement = valuesArg[placeholderName];
+        if (replacement === undefined || replacement === '') {
+          missingValues.add(placeholderName);
+          return match;
+        }
+        return replacement;
+      });
+      if (missingValues.size > 0) {
+        throw new Error(
+          `Missing template value(s) for ${key}: ${Array.from(missingValues).join(', ')}`,
+        );
+      }
+      envVarsArg[key] = resolvedValue;
+    }
+  }
+
   /**
    * Start auto-update monitoring for registry services
    * Polls every 30 seconds for digest changes and restarts services if needed