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/auto-reply/reply/directives.ts

@@ -1,4 +1,5 @@
 import type { NoticeLevel, ReasoningLevel } from "../thinking.js";
+import { escapeRegExp } from "../../utils.js";
 import {
   type ElevatedLevel,
   normalizeElevatedLevel,
@@ -17,8 +18,6 @@ type ExtractedLevel<T> = {
   hasDirective: boolean;
 };
 
-const escapeRegExp = (value: string) => value.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
-
 const matchLevelDirective = (
   body: string,
   names: string[],