Skip claude.ai/code and use word boundaries for mappings

Two user-reported conflicts when using the extension alongside Claude
Code on the web and with short mappings:

1. Claude Code (claude.ai/code) sends real file paths, usernames, and
   shell commands to its tool runtime. Substituting any of these
   corrupts execution, forcing users to disable the extension for that
   app. early-hook.js and injector.js now short-circuit on that path so
   fetch/XHR are never wrapped and no page-world script is injected.

2. Explicit mappings used raw literal regexes, so "not" -> "bad" would
   rewrite "nothing" into "badhing". substitute/reveal/scan/diff (and
   their page-world mirrors) now add \b on word-character edges only,
   leaving non-word edges like "@foo" unchanged so they keep matching.

https://claude.ai/code/session_01Y2YprLMx348eWD5C9Z4zpV

src/content/injector.js

@@ -15,6 +15,15 @@
   if (window.__silentSendInjected) return;
   window.__silentSendInjected = true;
 
+  // Skip Claude Code (web). Its tool-call traffic carries real paths/commands
+  // that must reach the runtime verbatim — substitution breaks execution.
+  if (
+    location.hostname === 'claude.ai' &&
+    /^\/code(\/|$)/.test(location.pathname)
+  ) {
+    return;
+  }
+
   // Merge active profiles into flat identity object
   function mergeProfiles(data) {
     const profiles = data?.profiles || [];