Add the option to chime after timer is finished

[austinliuu]

#82

Code generated with help from Codex and tested on my local HA instance

[ArikShemesh]

Hey @austinliuu, thanks for the contribution. But currently there's a fundamental browser limitation with the requested feature.

Browsers block audio unless the user has interacted with the page first. Your code primes the AudioContext when the user clicks Start, which works, but only if the timer was started in the same browser session.

If the timer was started from another device, or the page was reloaded while the timer was running, no user gesture has occurred in the current session. When the timer hits zero, the browser silently blocks the chime with no error or feedback to the user.

Two additional smaller issues:

AudioContext is never closed when the card is removed from DOM, causing a resource leak across dashboard navigation.
Oscillator nodes are never disconnected after oscillator.stop().

[L0bit0]

does the integration launch any event when it ends? as a workarround an automation to launch an alrt can be created, but we need to deiferentiate between this integration or any manula action.