Merge main into massive-terminal-upgrade

Resolves merge conflicts:
- apps/server/src/routes/terminal/common.ts: Keep randomBytes import, use @automaker/utils for createLogger
- apps/ui/eslint.config.mjs: Use main's explicit globals list with XMLHttpRequest and MediaQueryListEvent additions
- apps/ui/src/components/views/terminal-view.tsx: Keep our terminal improvements (killAllSessions, beforeunload, better error handling)
- apps/ui/src/config/terminal-themes.ts: Keep our search highlight colors for all themes
- apps/ui/src/store/app-store.ts: Keep our terminal settings persistence improvements (merge function)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

libs/utils/src/error-handler.ts

@@ -0,0 +1,131 @@
+/**
+ * Error handling utilities for standardized error classification
+ *
+ * Provides utilities for:
+ * - Detecting abort/cancellation errors
+ * - Detecting authentication errors
+ * - Classifying errors by type
+ * - Generating user-friendly error messages
+ */
+
+import type { ErrorType, ErrorInfo } from '@automaker/types';
+
+/**
+ * Check if an error is an abort/cancellation error
+ *
+ * @param error - The error to check
+ * @returns True if the error is an abort error
+ */
+export function isAbortError(error: unknown): boolean {
+  return error instanceof Error && (error.name === 'AbortError' || error.message.includes('abort'));
+}
+
+/**
+ * Check if an error is a user-initiated cancellation
+ *
+ * @param errorMessage - The error message to check
+ * @returns True if the error is a user-initiated cancellation
+ */
+export function isCancellationError(errorMessage: string): boolean {
+  const lowerMessage = errorMessage.toLowerCase();
+  return (
+    lowerMessage.includes('cancelled') ||
+    lowerMessage.includes('canceled') ||
+    lowerMessage.includes('stopped') ||
+    lowerMessage.includes('aborted')
+  );
+}
+
+/**
+ * Check if an error is an authentication/API key error
+ *
+ * @param errorMessage - The error message to check
+ * @returns True if the error is authentication-related
+ */
+export function isAuthenticationError(errorMessage: string): boolean {
+  return (
+    errorMessage.includes('Authentication failed') ||
+    errorMessage.includes('Invalid API key') ||
+    errorMessage.includes('authentication_failed') ||
+    errorMessage.includes('Fix external API key')
+  );
+}
+
+/**
+ * Classify an error into a specific type
+ *
+ * @param error - The error to classify
+ * @returns Classified error information
+ */
+export function classifyError(error: unknown): ErrorInfo {
+  const message = error instanceof Error ? error.message : String(error || 'Unknown error');
+  const isAbort = isAbortError(error);
+  const isAuth = isAuthenticationError(message);
+  const isCancellation = isCancellationError(message);
+
+  let type: ErrorType;
+  if (isAuth) {
+    type = 'authentication';
+  } else if (isAbort) {
+    type = 'abort';
+  } else if (isCancellation) {
+    type = 'cancellation';
+  } else if (error instanceof Error) {
+    type = 'execution';
+  } else {
+    type = 'unknown';
+  }
+
+  return {
+    type,
+    message,
+    isAbort,
+    isAuth,
+    isCancellation,
+    originalError: error,
+  };
+}
+
+/**
+ * Get a user-friendly error message
+ *
+ * @param error - The error to convert
+ * @returns User-friendly error message
+ */
+export function getUserFriendlyErrorMessage(error: unknown): string {
+  const info = classifyError(error);
+
+  if (info.isAbort) {
+    return 'Operation was cancelled';
+  }
+
+  if (info.isAuth) {
+    return 'Authentication failed. Please check your API key.';
+  }
+
+  return info.message;
+}
+
+/**
+ * Extract error message from an unknown error value
+ *
+ * Simple utility for getting a string error message from any error type.
+ * Returns the error's message property if it's an Error, otherwise
+ * converts to string. Used throughout the codebase for consistent
+ * error message extraction.
+ *
+ * @param error - The error value (Error object, string, or unknown)
+ * @returns Error message string
+ *
+ * @example
+ * ```typescript
+ * try {
+ *   throw new Error("Something went wrong");
+ * } catch (error) {
+ *   const message = getErrorMessage(error); // "Something went wrong"
+ * }
+ * ```
+ */
+export function getErrorMessage(error: unknown): string {
+  return error instanceof Error ? error.message : 'Unknown error';
+}