ward.lifecycle

local lifecycle = require("ward.lifecycle")

Lifecycle provides:

• Shutdown request detection (signals, cancellation)
• Hooks you can register to run before exit

Common pattern:

local lifecycle = require("ward.lifecycle")

lifecycle.on_shutdown(function(reason)
  -- flush files, cleanup temp dirs
end)

Functions:

• lifecycle.on(signal, fn) -> id - register a handler for a signal name/number ("HUP", "INT", "QUIT", "USR1", "USR2", "PIPE", "TERM", or a numeric code). Returns a handler id.
• lifecycle.on_shutdown(fn) -> id - register a shutdown callback (LIFO order).
• lifecycle.off(id) -> boolean - remove a previously registered handler.
• lifecycle.request(code?) -> () - request shutdown; code is an optional exit code.
• lifecycle.requested() -> boolean - whether shutdown has been requested.
• lifecycle.code() -> integer|nil - shutdown exit code (if known).

Notes:

• Ctrl-C / SIGINT requests shutdown by default.
• Shutdown callbacks run once in LIFO order; failures are best-effort and do not prevent later callbacks.