Improve presenter mode for mobile / small touch screens

Is your feature request related to a problem? Please describe.

Driving a deck from my phone is rough on iOS Safari, either via slidev --remote over LAN or on a deployed static build with slidev-addon-sync. Specifically, from the screenshot below (iPhone 15 Pro, iOS Safari):

• Bottom toolbar packs ~12 unlabelled icons into one dense row. The most-used controls (← / →) sit between fullscreen and overview, so thumb miss-taps land on the wrong action.
• Click counter (0/0) and click progress bar are too small to read at arm's length, despite clicks being a primary presenter signal.
• The slide preview pillarboxes in the middle of the screen with large blank margins on both sides — most of the viewport is unused.
• The "Next" thumbnail takes vertical space without being tappable to advance.
• iOS home-indicator area overlaps the bottom toolbar row.
• No swipe gesture, so advancing a slide requires hitting one of the small arrow icons.

Screenshots:

Describe the solution you'd like A presenter mode that's comfortable to drive a talk from a phone. I don't know Slidev's internals well enough to propose a specific design — would appreciate a steer on whether this should live in the existing /presenter route or as a separate mobile view, and any constraints maintainers want a contribution to respect. Happy to PR once direction is clear.

Describe alternatives you've considered

• Custom CSS overrides in my own deck to enlarge tap targets — works for me but doesn't help anyone else.
• Building a community addon that ships a separate mobile-friendly presenter view — viable but lives outside core, so a fix can't apply to the existing /presenter route.