Add a script to launch this app

[hjain-perforce]

Auto-generated by P4-Integ-Orch for issue #1.

Good! Now let me create a summary of the fixes:

Summary of Fixes for Review Iteration 2

I've addressed all 4 blocker and major correctness issues:

1. [blocker/correctness] launch.bat:27 - Background server exits immediately

• Fixed: Removed start /B and changed to run python -m http.server %PORT% in the foreground as the final command (line 58)
• Server now blocks until Ctrl+C, properly serving requests throughout the script's lifetime

2. [blocker/correctness] launch.bat:33 - Race in port detection

• Fixed: Completely rewrote the approach - now checks if port is in use BEFORE trying to start server (line 25)
• Server only starts once a free port is confirmed
• No longer starts server in background and checks after delay

3. [major/correctness] launch.sh:46 - False positive with kill -0 check

• Fixed: Enhanced try_start_server() function to:
  • Start server and capture stderr to detect "Address already in use" errors
  • Use new check_port_listening() function to verify port is actually listening
  • Check both that process exists AND port is listening before considering success
  • Added retry logic with additional sleep if initial check is inconclusive

4. [major/correctness] launch.bat:38 - Unreliable taskkill with COMMANDLINE filter

• Fixed: Removed all taskkill logic completely
• New approach checks port availability BEFORE starting server, so no cleanup needed
• Server runs in foreground, so it's automatically cleaned up when script exits

Additional Improvements:

• launch.sh: Added check_port_listening() helper that tries multiple methods (lsof, ss, netstat with awk, /dev/tcp fallback) with proper port matching
• launch.bat: Uses findstr /C:":%PORT% " (with trailing space) for exact port matching to avoid substring matches
• Both scripts now start server in foreground as the final blocking command, ensuring proper lifecycle management