// Package terminal provides direct ANSI terminal control with zero-alloc rendering.
//
// # Features
//
//   - True color (24-bit), 256-color, ANSI 16-color and colorless output, and
//     the terminal's own default colors
//   - Double-buffered output with cell-level diffing
//   - Raw input parsing with escape sequence handling and bracketed paste
//   - Key releases on request, from the Linux or FreeBSD console's keyboard
//     or the terminal's key event protocol (Alacritty's), and presses where
//     there are neither
//   - Drawing on /dev/tty when stdin or stdout is redirected (Unix)
//   - Resize detection (SIGWINCH on Unix, callback on WASM)
//   - Clean terminal restoration on exit/panic
//
// # Platform Support
//
// The package uses build tags to separate platform-specific code:
//
//   - unix: Native terminal via termios, unix.Poll, SIGWINCH
//   - wasm: Browser terminal via xterm.js JavaScript bridge
//
// # Architecture
//
// The Backend interface abstracts platform-specific operations:
//
//	Backend (interface)
//	├── unixBackend  (//go:build unix)  - termios, raw I/O, signals
//	└── wasmBackend  (//go:build wasm)  - syscall/js, callbacks
//
// Shared code (no build tags): Terminal interface, cell diffing, ANSI generation,
// escape sequence parsing.
//
// # WASM Integration
//
// WASM builds require JavaScript glue exposing these globals:
//
//	goTerminalWrite(Uint8Array)     // Go → JS: terminal output
//	goTerminalInput(Uint8Array)     // JS → Go: keyboard input
//	goTerminalResize(cols, rows)    // JS → Go: terminal resize
//	xterm.cols, xterm.rows          // Initial size query
//
// # Performance
//
// Output uses cell-level diffing. Only changed cells generate ANSI sequences.
// Style attributes are coalesced to minimize SGR calls. One goroutine writes
// what is rendered, so a terminal that stops reading never holds the caller:
// Flush keeps the newest frame until the write in flight returns, and Blocked
// reports how long it has waited.
// Input parsing is zero-allocation for common cases.
//
// This package bypasses terminfo/termcap entirely, emitting direct ANSI sequences.
// Target environments: Linux, macOS, BSDs with xterm-compatible terminals, and
// modern browsers with xterm.js.
package terminal