3 - Svelte playground - add more error triggers

[Reversean]

Closes #137

Added error triggers in svelte playground for testing HawkCatcher integration.

recording_2025-12-24_15.22.21.mp4

[FeironoX5]

No need in $props() & if statement, just do throw

[FeironoX5]

Rendering error report request is not being sent to Hawk Tracker because it intercepted by both onerror and failed.

[FeironoX5]

The approach here will be to implement customErrorHandler() and change handleBoundaryError() like this:

./+page.svelte:
function handleBoundaryError(error: Error) {
    console.error('🟡 [svelte:boundary] Caught rendering error:', error);
    customErrorHandler(error);
}

../../../hawk-related:
export let customErrorHandler: (message: Error | string) => void = (message): void => console.error(message);

...(see hoooks.client.ts review)

[FeironoX5]

Consider open/close behaviour with showError = !showError

[FeironoX5]

If implementing customErrorHandler() consider moving this part to ../../../hawk-related & wrapping like this so it could reassign customErrorHandler():

export const initHawk: () => void = () => {
  onMount(() => {
    if (browser && typeof localStorage !== 'undefined') {
      if (import.meta.env.VITE_HAWK_TOKEN) {
        const hawk = new Hawk({
          token: import.meta.env.VITE_HAWK_TOKEN,
        });

        customErrorHandler = (message) => hawk.send(message);
      }
    }
  });
};

Call initHawk() in script section of src/+layout.svelte as Hawk uses localStorage API available in browser enviroment only & sveltekit trying to do SSR.

[FeironoX5]

Just so we don't forget to change this