fix(node): mirror Grok hook loader contract

sdks/node/src/plugins/grok-contract.ts

@@ -25,6 +25,7 @@ export interface GrokHandler extends JsonObject {
   readonly command?: string;
   readonly url?: string;
   readonly timeout?: number;
+  readonly env?: Record<string, string> | null;
 }
 
 export interface GrokGroup extends JsonObject {
@@ -79,7 +80,7 @@ function validateHandler(
     throw new Error(`${label} requires a non-empty url`);
   }
   validateTimeout(value.timeout, label);
-  if (value.env !== undefined) {
+  if (value.env !== undefined && value.env !== null) {
     if (!isObject(value.env)
       || Object.values(value.env).some((item) => typeof item !== 'string')) {
       throw new Error(`${label} env must map names to strings`);

sdks/node/src/plugins/grok-io.ts

@@ -15,7 +15,12 @@ const CONFIG_FILE = 'elydora-audit.json';
 
 export function grokConfigPath(): string {
   const configured = process.env.GROK_HOME;
-  const grokHome = configured === undefined || configured === ''
+  if (configured === '') {
+    throw new Error(
+      'GROK_HOME is empty; unset GROK_HOME or set it to an absolute home directory',
+    );
+  }
+  const grokHome = configured === undefined
     ? path.join(os.homedir(), '.grok')
     : path.resolve(configured);
   return path.join(grokHome, 'hooks', CONFIG_FILE);