refactor: consolidate duplicate utility functions (#12439)

* refactor: consolidate duplicate utility functions

- Add escapeRegExp to src/utils.ts and remove 10 local duplicates
- Rename bash-tools clampNumber to clampWithDefault (different signature)
- Centralize formatError calls to use formatErrorMessage from infra/errors.ts
- Re-export formatErrorMessage from cli/cli-utils.ts to preserve API

* refactor: consolidate remaining escapeRegExp duplicates

* refactor: consolidate sleep, stripAnsi, and clamp duplicates

src/utils.ts

@@ -21,6 +21,16 @@ export function clampInt(value: number, min: number, max: number): number {
   return clampNumber(Math.floor(value), min, max);
 }
 
+/** Alias for clampNumber (shorter, more common name) */
+export const clamp = clampNumber;
+
+/**
+ * Escapes special regex characters in a string so it can be used in a RegExp constructor.
+ */
+export function escapeRegExp(value: string): string {
+  return value.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+}
+
 export type WebChannel = "web";
 
 export function assertWebChannel(input: string): asserts input is WebChannel {