feat(web): complete clip editor beatmaking parity

[txbrown]

Summary

Web users can now edit clips and perform on-screen instruments without stuck notes or reduced piano-roll controls. The piano roll supports adding, deleting, moving, and resizing notes with live previews, while shared interaction math keeps native behavior unchanged.

What changed

• Extracted note hit-testing, move, resize, and tap calculations into shared piano-roll math used by native and web.
• Added mouse and touch pointer editing to the web grid, including immediate mouse drags, a 250 ms touch hold, pointer capture, resize handles, and original-position ghosts.
• Balanced pad and QWERTY press/release lifecycles across pointer exit, capture loss, browser blur, visibility changes, and unmount.
• Preserved pad ownership when multiple pointers share a cell and isolated piano-roll editing to one pointer at a time.
• Bounded add, move, and resize operations to the clip while deriving pitch movement from the note rather than expanded hit padding.
• Added labeled keyboard add/move/pitch/resize/delete paths for accessibility and automation.
• Strengthened beat and measure separators without changing the clip editor layout.
• Added focused interaction, input lifecycle, shared-math, and snapshot coverage.
• Refreshed stale account snapshots and formatting that were already blocking the full CI suite.

Validation

• Full Circuit UI suite passes: 265 tests, 1 todo, and 37 snapshots.
• Circuit UI workspace and build TypeScript checks pass.
• Changed-file ESLint passes.
• Expo web export passes through the consuming app.
• Browser QA confirmed pad release plus piano-roll add, delete, move, resize, and preview behavior.

Physical touch-device verification remains required before merge because the 250 ms hold gesture changes interaction feel.

---