UI: Popover Component

[mihar-22]

Blocked by:

• Common Core Contracts #219
• Docs: Demo Setup #221
• Chore: Test Utilities #242

Implement a compound Popover component for Video.js 10, providing the foundation for tooltips, menus, and other floating UI elements.

The Popover handles positioning, interactions, transitions/animations, safe polygons, and collision avoidance.

References

• Base UI: Popover — Primary API reference
• Radix: Popover
• Popover Attribute (MDN)
• CSS Anchor Positioning
• Floating UI — Positioning engine (fallback)
• Component Behavior Definitions & Hooks #198