fix: recognize btch-dev@ release tags in update checker

normalizeReleaseVersion only stripped btch-cli@/v prefixes, so the
btch-dev@ tags published by the release workflow were never matched
and update checks silently reported nothing.

🤖 Generated with Codebuff
Co-Authored-By: Codebuff <noreply@codebuff.com>

Author: BOTCAHX

src/utils/install-manager.ts

@@ -331,6 +331,7 @@ async function fetchReleaseJson(url: string): Promise<GitHubRelease | null> {
 
 function normalizeReleaseVersion(tagName: string): string | null {
   let version = tagName;
+  if (version.startsWith("btch-dev@")) version = version.slice("btch-dev@".length);
   if (version.startsWith("btch-cli@")) version = version.slice("btch-cli@".length);
   if (version.startsWith("v")) version = version.slice(1);
   return semverValid(version);