Problem

codedb does not compile or run on Windows. The build system, stack allocation, and heap allocation strategies are Linux/macOS-only:

• Default Windows stack is 1MB vs Linux 8MB — LLVM merges all command branch frames into one ~128MB frame, causing STATUS_STACK_OVERFLOW
• EventQueue stores 4096 × ~1KB FsEvent inline (~4MB on stack) — exceeds Windows stack
• Frequency table working buffers ([256][256]u64 = 512KB + [256][256]u16 = 128KB) are stack-allocated
• std.fs.max_path_bytes is 32KB on Windows vs 4KB on POSIX — path buffers blow the stack when multiplied across structs

Expected Behavior

zig build -Dtarget=x86_64-windows cross-compiles successfully. On Windows, codedb <root> tree runs without stack overflow.

Scope

• build.zig: set exe.stack_size = 8MB for Windows targets
• src/compat.zig: add path_buf_size constant (1024 on Windows, max_path_bytes elsewhere)
• src/main.zig: noinline trampoline to prevent LLVM frame merging; fix double scan_thread.join() (UB on all platforms)
• src/watcher.zig: heap-allocate EventQueue events array via page_allocator; use path_buf_size for FsEvent.path_buf
• src/index.zig: heap-allocate frequency table counts and out buffers
• src/tests.zig: update 3 EventQueue tests to use init()/deinit() API