chore: import upstream snapshot with attribution

apps/webapp/app/v3/deduplicateVariableArray.server.ts

@@ -0,0 +1,14 @@
+import { type EnvironmentVariable } from "./environmentVariables/repository";
+
+/** Later variables override earlier ones */
+export function deduplicateVariableArray(variables: EnvironmentVariable[]) {
+  const result: EnvironmentVariable[] = [];
+  // Process array in reverse order so later variables override earlier ones
+  for (const variable of [...variables].reverse()) {
+    if (!result.some((v) => v.key === variable.key)) {
+      result.push(variable);
+    }
+  }
+  // Reverse back to maintain original order but with later variables taking precedence
+  return result.reverse();
+}