CVE-2026-63496: augment-vir: Shell Command Injection in `grep()` via Unsanitized `searchPattern`

augment-vir is a collection of helper functions. Prior to version 31.73.5, the grep() function exported by @augment-vir/node inserts caller-controlled search patterns directly into a double-quoted shell command string without sanitization (grep.ts:310). When the constructed command is passed to spawn() with shell: 'bash' (shell.ts:98-99), bash evaluates $() command substitution expressions embedded in the pattern, resulting in arbitrary OS command execution as the Node.js process user. Any downstream application that passes untrusted input to grep()'s pattern or patterns field is vulnerable to unauthenticated local (and potentially remote) code execution. This issue has been patched in version 31.73.5.