fix(HappyHare): Fixed animated filament position and greatly cleaned up component

[moggieuk]

Description:
This fixes a couple of cases where the (animated) position of the filament in the bowden was incorrect. It fixes the bug of reading gate_endstop where extruder_endstop should have been used.
It also greatly simplifies the component and removes private methods and unnecessary watchers.

Component modified:

SIgned off by: Paul Morgan (moggieuk@hotmail.com)

[moggieuk]

@pedrolamas This PR is a combination bug fix and significant component code-cleanup. It is the last of the current batch of PRs. Thank you!

[Copilot]

Pull request overview

This PR fixes a critical bug where configGateHomingEndstop was incorrectly used instead of configExtruderHomingEndstop when determining the end-of-bowden filament position, and significantly refactors the component by replacing watchers and imperative animation logic with reactive computed properties.

• Fixes incorrect endstop configuration check causing wrong filament position calculation
• Refactors from imperative watchers to reactive computed properties for cleaner state management
• Simplifies animation logic with CSS transitions instead of programmatic animation

[Copilot]

The return type should include undefined since accessing a non-existent key in the sensors Record returns undefined at runtime. This would improve type safety when using this getter. Consider changing the return type to boolean | null | undefined or adding a check like this.sensors['toolhead'] ?? null to match the declared type.

Suggested change

	get toolheadSensor () {
	get toolheadSensor (): boolean | null | undefined {

[pedrolamas]

Ignore.