fix: update npm username regex to support underscores and dots (#1134)

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
Co-authored-by: Daniel Roe <daniel@roe.dev>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

Author: 4 people

shared/schemas/user.ts

@@ -1,6 +1,6 @@
 import * as v from 'valibot'
 
-const NPM_USERNAME_RE = /^[a-z0-9]([a-z0-9-]*[a-z0-9])?$/i
+const NPM_USERNAME_RE = /^[a-z0-9]([\w.-]*[a-z0-9])?$/i
 const NPM_USERNAME_MAX_LENGTH = 50
 
 /**