Delegate to Turbo's view-transitions if enabled

[pascallaliberte]

Fixes #19

Makes Turn automatically detect when <meta name="view-transition" content="same-origin"> is present and disables its own view transitions, letting Turbo handle them natively. This solves the redirect abort issue while preserving Turn's CSS animation capabilities.

Detecting if the page has the view-transition same-origin meta tag

With this PR, Turn auto-detects the native view-transition meta tag and delegates to Turbo when present. This works per-page (like data-turn="false"), giving us control over which pages use Turn's view transitions vs Turbo's native handling.

This works because:

• Turbo's ViewTransitioner naturally spans the entire navigation, including redirect follow-ups
• Turn's exit animation completes before render (unaffected by redirect)
• Turbo's view transition handles the DOM swap
• Turn's enter animation runs after render (unaffected by redirect)
• The reset() call on redirect follow-up has nothing to abort - NullTurn.abort() is a no-op