Improve Git monorepo performance with a file system monitor

This post introduces and details the new builtin FSMonitor `git fsmonitor--daemon` feature in Git version 2.37.0. It explains how FSMonitor improves Git performance in large monorepos by reducing the time spent on worktree searches for commands like `git status` and `git add`. The post covers the FSMonitor architecture, including its daemon process, registration with the OS for change notifications, and IPC communication with Git clients. It elaborates on the synchronization mechanism using tokens, PIDs, and SIDs to ensure data integrity and handle potential event drops. The post also provides performance data demonstrating significant speedups on large repositories and explains the different types of files Git considers during worktree searches.