feat: add locatelocationfound event

[KristjanESPERANTO]

I looked at PR #343, which has been open since 2023. The implementation had issues, but the use case is valid. This PR here takes a different approach - using an event instead of a callback option - which is more flexible and consistent with Leaflet's patterns.

Why is this useful?

Some practical scenarios I can imagine would need access to the control when location is found:

• One-shot location - Get user location once, then stop (e.g., "show nearby restaurants")
• Custom zoom - Fit bounds to include user + target marker (urb4nc4rl's use case from added oneshot callback (trigger, then stop) when location is found #343)
• Geofencing - Check if user is in delivery area
• Analytics - Track accuracy and behavior
• Form autofill - Reverse geocode address

Why add it to the plugin?

"Can't you just use map.locate() directly without the plugin?"

Yes, but the plugin provides UI, marker rendering, accuracy circles, compass, zoom behavior, popups, error handling, and visual states. Most apps use the plugin for this functionality.

"Then just listen to the native locationfound event?"

You can:

const lc = L.control.locate().addTo(map);
map.on('locationfound', (e) => {
  lc.stop();
});

But this requires keeping a separate control reference - extra boilerplate.

What this PR does

Adds a locatelocationfound event with direct control access:

map.on('locatelocationfound', (e) => {
  console.log(e.latlng, e.accuracy);
  e.control.stop(); // No separate reference needed
});

This matches the existing pattern - locateactivate, locatedeactivate, and locationtimeout already pass the control instance.

Changes:

• New event with TypeScript types
• Tests added
• Docs updated

[domoritz]

Would this work?

Suggested change

	// Fire event with location data and control reference
	this._map.fire("locatelocationfound", {
	latlng: e.latlng,
	accuracy: e.accuracy,
	altitude: e.altitude,
	altitudeAccuracy: e.altitudeAccuracy,
	heading: e.heading,
	speed: e.speed,
	timestamp: e.timestamp,
	bounds: e.bounds,
	control: this
	});
	// Fire event with location data and control reference
	this._map.fire("locatelocationfound", {
	...e,
	control: this
	});

[KristjanESPERANTO]

Wow. That's much more elegant and future-proof - if Leaflet ever adds new properties to the locationfound event, they will be automatically passed through. Just changed it.

[domoritz]

Is this type somewhere in leaflet as well? Would be nice not to redeclare.

[KristjanESPERANTO]

No, LocateLocationFoundEvent doesn't exist in Leaflet. But I just changed it to extends LocationEvent - so we only declare what's actually new (the control property) and inherit everything else from Leaflet's existing type. Much cleaner, just like the ...e spread in the implementation.

[KristjanESPERANTO]

Just removed the LatLng import after your approval - not needed since the switch to extends LocationEvent - LocationEvent already includes it.