fc2c3c2c7c
- Fixed persistent shell session state not being reset after command abort or hard timeout. - Fixed hard timeout handling to properly interrupt long-running commands exceeding grace period. - Introduced hard timeout mechanism with Promise.race() to enforce absolute timeout limit and prevent command hangs. - Replaced shell command execution with explicit timeout and SIGKILL signal handling in shell-snapshot. - Simplified bash command normalization to use only explicit head/tail parameters from tool input. - Exported getAntigravityUserAgent() function for centralized User-Agent header construction.