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/mentions.ts

@@ -3,10 +3,7 @@ import type { MsgContext } from "../templating.js";
 import { resolveAgentConfig } from "../../agents/agent-scope.js";
 import { getChannelDock } from "../../channels/dock.js";
 import { normalizeChannelId } from "../../channels/plugins/index.js";
-
-function escapeRegExp(text: string): string {
-  return text.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
-}
+import { escapeRegExp } from "../../utils.js";
 
 function deriveMentionPatterns(identity?: { name?: string; emoji?: string }) {
   const patterns: string[] = [];