Refactor: Store helpers in globalVariableContext instead of separate variable

Changes:
- Store helpers object in globalVariableContext.helpers
- Remove separate 'helpers' variable and helpersContext
- Helpers now spread into context via ...globalVariableContext
- Simplifies context injection - all globals in one place

Benefits:
- More consistent with JSON data loading pattern
- Single source of truth (globalVariableContext) for all VM globals
- Cleaner context creation (no separate helpers variable)
- helpers treated same as other global objects

Implementation:
- loadHelpers() now mutates globalVariableContext instead of returning
- Use tempContext for helpers execution (discarded after use)
- helpers accessible as 'helpers' in proxy.js via spread operator

Testing:
- ✓ Syntax validated
- ✓ helpers accessible in VM context
- ✓ Spread operator includes both JSON data and helpers
- ✓ All 11 helper functions available

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/server.js

@@ -69,10 +69,8 @@ function loadGlobalObjects() {
 }
 
 /**
- * Load helpers module using vm.Script
+ * Load helpers module using vm.Script and store in globalVariableContext
  * Pattern: helpers.js returns object with utility functions via IIFE
- * 
- * @returns {Object} Helpers object with all utility functions
  */
 function loadHelpers() {
   const helpersPath = join(__dirname, "globalVariables", "helpers.js");
@@ -81,21 +79,21 @@ function loadHelpers() {
     const helpersCode = readFileSync(helpersPath, "utf-8");
     const helpersScript = new vm.Script(helpersCode, { filename: "helpers.js" });
     
-    // Create isolated context for helpers (needs crypto and console)
+    // Execute helpers.js in context with crypto and console
-    const helpersContext = vm.createContext({
+    // Returns object with all helper functions
+    const tempContext = vm.createContext({
       crypto,
       console: logger,
     });
+    const helpers = helpersScript.runInContext(tempContext);
     
-    // Execute helpers.js and get the returned object
+    // Store in globalVariableContext to be spread into per-request context
-    const helpers = helpersScript.runInContext(helpersContext);
+    globalVariableContext.helpers = helpers;
     
     logger.info("Loaded helpers module", {
       functions: Object.keys(helpers).length,
       exports: Object.keys(helpers),
     });
-    
-    return helpers;
   } catch (error) {
     logger.error("Failed to load helpers module", {
       path: helpersPath,
@@ -160,8 +158,8 @@ async function startServer() {
     // Load global objects from globalVariables/ directory (e.g., service account keys)
     loadGlobalObjects();
 
-    // Load helpers module via vm.Script
+    // Load helpers module via vm.Script and add to globalVariableContext
-    const helpers = loadHelpers();
+    loadHelpers();
 
     logger.info("Starting Proxy Script Server...");
     logger.info(
@@ -184,10 +182,10 @@ async function startServer() {
     const server = http.createServer((req, res) => {
       try {
         // Create a context with all globals that proxy.js needs
+        // globalVariableContext includes both JSON data and helpers object
         const context = vm.createContext({
           ...globalVMContext,
           ...globalVariableContext,
-          helpers,
           req,
           res,
         });