feat(renderer): rotated labels on mixed-zone cards

[LeslieOA]

Summary

cc-label-left / cc-label-right rotated 90° only on label-only cards. On mixed-zone cards (a label combined with body / header / footer) the label fell back to horizontal — because its rotation <Group transform> had to sit inside SkiaTextRenderer's multi-zone elements array, and <Group transform> is a no-op when nested in an element array (react-native-skia limitation, #96).

Closes #64 (split out from #53).

Fix

• New SkiaCardLabelRenderer — returns the rotated label as its own top-level <Group transform>, rendered as a sibling in SkiaCanvasLayer. Top-level placement is what makes the transform apply (same principle as the label-only early-return that already worked). Handles all side labels — label-only and mixed alike — and clips to the card outline (reuses #53a's shapeClipPath).
• SkiaTextRenderer no longer renders labels: removed the label-only early-return and the horizontal mixed-zone fallback (plus the now-unused getLabels import + labels memo). Draws header / footer / body only.
• Picture path (drawTextNode): replaced the label-only special-case with a unified loop drawing every label rotated, for both label-only and mixed cards — keeps the pinch overlay pixel-identical to the live tree.

Why low-risk

• The rotation maths is unchanged — lifted verbatim from the working label-only path, just relocated to a top-level return.
• Label-only cards: SkiaTextRenderer now returns null for them (empty elements), and the label renderer draws them — net-identical output.
• typecheck / lint / 48 tests all green.

Test plan

• On-device: a card with both a cc-label-left and body text shows the label rotated 90° (previously horizontal). Candy label fixtures: Headers and Labels.canvas, candy-feature-*.
• Label-only cards still rotate correctly (no regression).
• Left + right labels on the same card both rotate.
• Pinch-zoom: Picture overlay matches the live tree (no label flip/flash).

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