fix: installer hangs on Git Bash due to backslash in heredoc

Replace `home_dir.replace('\', '/')` with `home_dir.replace(os.sep, '/')`
in the embedded Python script. The literal `\` inside a bash heredoc gets
reduced to a single `\` by Git Bash on Windows, causing a Python
SyntaxError (unterminated string literal) that silently hangs the
installer at step 6.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ChanMeng666

scripts/install-complete.sh

@@ -505,7 +505,7 @@ try:
 
     if is_windows:
         # Windows: Use Python hook_runner.py for reliable execution
-        hooks_dir = home_dir.replace('\\', '/') + '/.claude/hooks'
+        hooks_dir = home_dir.replace(os.sep, '/') + '/.claude/hooks'
         hook_runner = f'{hooks_dir}/hook_runner.py'
 
         for hook_name, hook_type in all_hook_types.items():