Fix fatal error booting screens without a mount() method

[siddiqar]

What

WebScreenRunner::boot() invoked $component->mount() directly. Core's NativeComponent deliberately declares no mount(); it exposes the guarded mountComponent() entrypoint instead (a no-op when the component has no mount(), and route-binding + DI when it does), which NativeRouter also uses on device. Any screen without a mount() method therefore fatals in the browser:

Call to undefined method App\NativeComponents\Home::mount()
 at vendor/nativephp/web-ui/src/Protocol/WebScreenRunner.php:441

Reproduction

Route a screen that defines no mount():

Route::native('/', App\NativeComponents\Home::class);

GET / returns 500 before this change, 200 after.

Fix

Call mountComponent() instead (parity with NativeRouter::preloadStack() / the device run loop). Both mounting paths go through boot(), so this covers the initial GET and the {type: 'lazy'} update.

Also adds a CHANGELOG.md entry under [Unreleased].

Verification

• Consuming app: nativephp/superstack starter, nativephp/mobile 4.6.0.
• Browser (macOS): GET / renders <title>Super Stack</title>, HTTP 200; before the change, HTTP 500 with the trace above.

Notes

• Per CONTRIBUTING, the behaviour test belongs in the nativephp/mobile suite (tests/Feature/Edge/, Web*). Happy to add/link it — let me know where you'd like it.
• mountComponent() exists in nativephp/mobile 4.6.0. This package supports ^4.4; if mountComponent() is newer than that, a method_exists() guard would be warranted. Flagging in case you'd prefer the guarded form.