AnimatedSearchBarConfig colors are hardcoded, not MaterialTheme-aware

[cloudigits]

Same underlying problem as #13 (which only covered AnimatedSearchBarTextConfig), but for AnimatedSearchBarConfig — none of these adapt to the app's theme:

• searchBarBackgroundColor → Color.White
• searchBarBorderColor → Color(0xFFE0E0E0)
• iconBackgroundColor → Color(0xFF558B2F)
• iconTint → Color.White
• clearIconTint → Color.Black

The component's own KDoc advertises "Configurable ... colors ..." and "Fully customizable through AnimatedSearchBarConfig," so this reads as the same class of defect as #13 rather than a missing feature — a dark-themed app gets a white search bar with black icons by default, with no crash but silently wrong output.

Not a crash, just a silent theming defect — usability/accessibility impact rather than a functional break, for triage purposes.

Suggested fix, matching M3 role pairing:

• searchBarBackgroundColor → colorScheme.surfaceContainerHigh
• searchBarBorderColor → colorScheme.outlineVariant
• iconBackgroundColor → colorScheme.primaryContainer
• iconTint → colorScheme.onPrimaryContainer
• clearIconTint → colorScheme.onSurfaceVariant

Related: #13