Multiple fixes for tutorial regression issues:
- Fix overlay rendering: Changed from <g> to <foreignObject> to support
DOM components (Radix UI Tooltip), fixing hydration errors
- Fix overlay positioning: Use calculateBeadPosition for accurate placement
- Fix arrow indicators: Reduce size, fix transform origin for center-based
scaling, correct direction logic for heaven vs earth beads, add black
stroke for contrast on yellow backgrounds, remove unnecessary circle
- Fix bead visibility: Implement proper opacity cascade (customStyle ->
active -> hideInactiveBeads + hover), use opacity 0 instead of
conditional rendering to enable hover detection
- Add abacus-level hover: Track hover state at abacus level and propagate
to beads so inactive beads appear on hover over any part of abacus
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
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