fix: preserve native space trackpad feedback

[MeliValesca]

Space-trackpad feedback now follows the observed native states: iOS fades legends and softens key faces, uses a visible gray pressed fill, and restores appearance on release/cancellation. Android keeps the space bar's configured pressed color during cursor dragging. Custom colors remain supported and iOS letter-preview bubbles keep their independent fill.

Adds atomic feedback regressions to the existing CI suites, plus a stationary iPad currency-hold regression. Removes two unused image fixtures and three obsolete manual visual scripts.

The iPad CI failure was in Apple's dollar-hold baseline: the recording showed a highlighted cent sign but a stationary release committed nothing. The UI comparison now explicitly slides into the currency popup, requires ¢, and compares Keyflow's output exactly. Keyflow's stationary hold/release remains covered directly. No retry or skip was added for that failure.

Validation

• Library checks passed (format, lint, types, Jest, visual helpers, CI inventory and package build).
• Android: full native instrumentation suite passed locally on phone and tablet (63 cases each); both GitHub device jobs passed on the preceding code commit.
• iOS: full rendering suites passed locally on iPhone and iPad (50 cases before platform-specific skips).
• All punctuation-hold comparisons passed locally: six iPhone cases and four iPad cases. The final strict iPad dollar test passed three consecutive runs.
• Space-trackpad cursor comparisons passed on iPhone/iPad; consecutive video frames were inspected for native and Keyflow feedback.
• GitHub CI runs the full interaction suites; the entire 60-case suite was not rerun locally for this test-only correction.