Add imperative resizing feature

[kantum]

I needed to implement double click to resize my panes to default.

I didn't find a way to do it, does this implementation follows your philosophy?

[Copilot]

Pull request overview

Adds a new server-pushed resize event to imperatively resize a pane (by percentage) and includes a Demo LiveView page showcasing the behavior.

Changes:

• Documented server-side events (collapse, expand, resize) in LivePane module docs.
• Added a new resize server event handler in the pane JS hook to resize a pane to a target percentage (with clamping).
• Added a new demo route + LiveView/page to demonstrate imperative resizing.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
lib/live_pane.ex	Documents the new resize server event alongside existing server-driven events.
assets/js/live_pane/hooks/pane.ts	Implements the client-side handler and layout adjustment logic for server-pushed resize.
demo/lib/demo_web/router.ex	Adds a /resize LiveView route in the demo app.
demo/lib/demo_web/components/layouts.ex	Adds navigation link to the new resize demo page.
demo/lib/demo_web/live/resize_live.ex	Demo LiveView that pushes the resize event from the server.
demo/lib/demo_web/live/resize_live.html.heex	Demo UI for selecting a size and triggering the server-side resize.

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[giusdp]

Hey thanks a ton for the contribution!! Soon I'll review and merge 😄

btw I don't remember enabling any automatic copilot review wtf

[giusdp]

Awesome work, thank you!