useDebounce race condition when already running -> can lose new call

[Coronon]

Describe the bug

While working on #134 I noticed that all scheduled calls will resolve the callback and then call reset, which sets timeout to undefined. I first though that this could lead to calls that are debounced while the callback handler is already running to not be cancelable. It turns out that they can simply get completely lost:
When the setTimeout is finally called, resolve can already be null from the previous runs reset call, which will lead to the actual callback to never be called.

While I don't think the later callback should simply be lost, this could be one of those: "It's a feature, not a bug" instances. Either way the behavior should be clearly documented.

Reproduction

https://stackblitz.com/edit/sveltejs-kit-template-default-bpdvwu?file=src%2Froutes%2F%2Bpage.svelte

Logs

No response

System Info

System:
    OS: macOS 15.1
    CPU: (12) arm64 Apple M2 Max
    Memory: 24.22 GB / 64.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 23.1.0 - /opt/homebrew/bin/node
    npm: 10.9.0 - /opt/homebrew/bin/npm
    pnpm: 9.12.3 - /opt/homebrew/bin/pnpm
  Browsers:
    Chrome: 130.0.6723.92
    Safari: 18.1

Severity

annoyance