feat(bolt): white-core glow pulse for in-flight zap

[dmnyc]

Slim carve-out from #556. Single-file animation rewrite of the action-bar bolt for in-flight zaps. Ports iOS commit #6 from feat/one-tap-zap.

What changes

Replaces the existing alpha+scale LightningAnimation (tween(600) reverse-repeat) with a sin-eased single-oscillator on a 0.9s period:

• sine ∈ [-1, 1], phase ∈ [0, 1] = (sine + 1) / 2
• iconScale = 1.0 + 0.10 * sine (0.90 → 1.10)
• verticalOffset = -0.5 * sine (±0.5dp, centered on baseline — kept tight so the bolt doesn't lift off the action-bar baseline and misalign with neighbouring glyphs)

The silhouette stays solid white; three stacked stroked shadows behind it do the warm-glow work:

• Inner stroke — 1.5dp, constant width, holds the white core's outline
• Medium glow — 4 + 3·phase dp, breathes with the phase
• Outer halo — 8 + 6·phase dp, widest bleed, breathes with the phase, alpha 0.3 → 0.8

All three shadows tint with WispThemeColors.zapColor.

Note for reviewer

Main already has WispThemeColors.zapAnimationColor (added by #558) — a vivid-floored variant of zapColor specifically for animations so the burst never reads muddy on light backgrounds. The bolt animation still tints with zapColor in this PR to keep the carve-out faithful to the original commit; we can swap to zapAnimationColor here in a follow-up if that's preferred.

Files

• app/src/main/kotlin/com/wisp/app/ui/component/ActionBar.kt (+52 / −35)

Test plan

• Trigger an in-flight zap (any send-zap action) → bolt pulses with a soft warm halo around a solid white core
• Light mode: glow reads as warm orange against the near-white background, not as a flat alpha smear
• Dark mode: glow reads as vivid orange against the near-black background
• Bolt stays anchored on the action-bar baseline — no vertical wobble visible against neighbouring icons

Carve-out context

PRs in the series so far: #570 (wallet setup polish), #571 (wallet dashboard polish), #572 (drop relay-backup status list).