feat(lint): add rotation_pivot_drift layout check (#2741)

## What
New cross-sample layout check `rotation_pivot_drift` — flags a rotating element that should spin **in place** but pivots about the **wrong point** (e.g. a wheel whose spokes use a hardcoded px `transformOrigin` instead of `svgOrigin`/`%`, so they swing off-center while every existing check still passes).

Motivating prod case: a portrait ad's spoked-wheel whose `#spokes` rotated about `transformOrigin:"250px 250px"` in a resized 460px container — spokes detached from the hub, shipped clean because no rule inspects rotation.

## How
- `layout-audit.browser.js`: `window.__hyperframesRotationSample()` reports each visible transformed element's bbox center + decoded rotation angle per layout sample. Skips `[data-layout-allow-orbit]`.
- `checkPipeline.ts`: accumulates samples across the seek grid; `detectRotationPivotDrift()` (modeled on `detectSweepStatic`) flags an element that (a) actually spins (angle spread > 20° over ≥3 samples), (b) is size-stable (bbox width ratio ≤ 1.6), and (c) whose bbox **center** drifts > `max(10% of its size, 2% of min viewport dim)`. Emits `warning`; not persistence-tiered (not demoted to info).

## FP guards
Real rotation required, ≥3 samples, size stability, `data-layout-allow-orbit` exemption, min area ~2500px². Center-drift (not bbox size) is the discriminator, so a correctly-centered spinner reads drift ≈ 0.

## Validation (`check --json`)
| Fixture | Expected | Result |
|---|---|---|
| off-transformOrigin spoked wheel | fire | **fired — 109px drift on `#spokes`** |
| non-spinning comps (node diagram, device tree) | clean | clean, no FP |
| correctly-centered spinner (`svgOrigin`) | clean | clean (spins 162°, drift 0) |
| `data-layout-allow-orbit` off-origin spinner | clean | clean (exempt) |
| off-`svgOrigin` control, no opt-out | fire | fired — 251px drift |

No false positives. `tsc --noEmit` clean, `oxlint` clean, `check.test.ts` + `layout-audit.browser.test.ts` = 112/112 pass.

## Note
`ROTATION_MAX_SIZE_RATIO` is 1.6 (not 1.3): a rotating anisotropic shape's axis-aligned bbox inherently oscillates (8-spoke star ~1.32×, square 1.41×), so a tighter ratio rejects legitimate targets. Center-drift stays the real discriminator; thin swinging bars are excluded.

Follow-up: a `detectRotationPivotDrift` unit test via the fake driver's `collectRotationSample` (mirroring the sweep_static tests).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

packages/cli/src/commands/check.test.ts

@@ -149,6 +149,7 @@ function fakeDriver(overrides: Partial<CheckAuditDriver> = {}): CheckAuditDriver
     seek: vi.fn(async (_time: number) => undefined),
     collectLayout: vi.fn(async (_time: number, _tolerance: number) => []),
     collectLayoutGeometry: vi.fn(async () => `geometry-${geometryCallCount++}`),
+    collectRotationSample: vi.fn(async (_time: number) => []),
     collectGeometryCandidates: vi.fn(async () => []),
     collectMotionFrame: vi.fn(async (time: number) => ({ time, data: {}, liveness: {} })),
     anchorMotionIssues: vi.fn(async (issues: LayoutIssue[]) =>