chore: import upstream snapshot with attribution

apps/sim/lib/tokenization/errors.ts

@@ -0,0 +1,23 @@
+/**
+ * Custom error classes for tokenization functionality
+ */
+
+export class TokenizationError extends Error {
+  public readonly code: 'INVALID_PROVIDER' | 'MISSING_TEXT' | 'CALCULATION_FAILED' | 'INVALID_MODEL'
+  public readonly details?: Record<string, unknown>
+
+  constructor(message: string, code: TokenizationError['code'], details?: Record<string, unknown>) {
+    super(message)
+    this.name = 'TokenizationError'
+    this.code = code
+    this.details = details
+  }
+}
+
+export function createTokenizationError(
+  code: TokenizationError['code'],
+  message: string,
+  details?: Record<string, unknown>
+): TokenizationError {
+  return new TokenizationError(message, code, details)
+}