• customColors: bring your own palette — colors are distributed cyclically over the gradient slots and rendered as supplied (hue-shift disabled).
• Oversized borderRadius values are clamped to the box, so 999 produces a stadium/pill shape (matching CSS behavior).
• Blur filters use TileMode.decal for CSS-accurate edge behavior.

Initial release — a Flutter port of border-beam by Jakub Antalik (visual parity with its v1.3.0).

• All five types: sm, md, line, pulse-inner, pulse-outside
• Four color variants: colorful, mono, ocean, sunset
• Dark / light / auto themes, strength, duration, active with fade in/out callbacks, hue-shift controls, and the pulse consumer tuning hooks (glowBoost, coreBlur, bloomBlur, glowBrightness, glowSaturation, layer opacity factors)
• Performance: the pulse breathing is frame-capped to ~30fps, the heavy blurred bloom layers are frozen and cached as rasters (only a cheap hue-rotate color filter varies per frame), the wrapped child sits in its own RepaintBoundary and never repaints, and all tickers stop while the effect is inactive.

Known limitation: rendering is designed for Impeller/Skia native targets (iOS, Android, macOS, Windows, Linux). Flutter Web's renderer mishandles the saveLayer blend-mode masking the rotate/line types rely on, so web is not supported.