feat(wallet-setup): primary Spark mode + More-options accordion

[dmnyc]

First in a series of slim carve-outs from #556 (closing soon). Pure UI / no behavioural change — just makes the obvious next step visually obvious. Ports iOS commit #3 from feat/one-tap-zap.

What changes

Mode picker (screen 1):

• Spark row → full-bleed orange card with white text + icon, layered shadow glow (two stacked shadows in WispThemeColors.zapColor — wide outer + tighter inner — for the iOS bloom)
• NWC keeps its dark surface-variant peer treatment. Not buried under "More options" per spec — it's a genuine alternative

Spark sub-screen (screen 2):

• "Use my default wallet" gets the same primary treatment (orange fill + glow stack) so the nsec-derived recovery path reads as the obvious first choice
• Create new / Restore from seed phrase / Restore from relays collapse under a "More options" disclosure with a chevron that rotates 0→180° via animateFloatAsState. Expand defaults to open if there's no default-wallet option visible (so users who can't derive still see all paths immediately)
• AnimatedVisibility wraps the inner column for the expand/collapse transition (expandVertically + fadeIn / shrinkVertically + fadeOut), matching the iOS "fade rows in/out" cue

Scope

One file: app/src/main/kotlin/com/wisp/app/ui/screen/WalletScreen.kt (+148 / -26).

Test plan

• Mode picker shows Spark as glowing orange card, NWC as dark surface-variant peer
• Tap NWC → goes to NWC setup
• Tap Spark → goes to Spark sub-screen
• On Spark sub-screen with default-wallet available: orange "Use my default wallet" row visible, "More options" collapsed by default. Tap to expand → other paths fade in.
• On Spark sub-screen with no default-wallet (e.g. fresh install): "More options" expanded by default, all paths immediately visible.

Carve-out context

Replaces the equivalent work in #556. Other slim PRs follow for the remaining concerns:

• Wallet dashboard polish (top-5 tx, NWC paste reorder, parity polish)
• Bolt glow pulse animation
• Zap sheet pin Send button + recipient wiring
• Zap sheet iOS-layout rewrite + in-sheet toggle
• Instant zap (long-press) + Interface settings section
• Hero-input composer + Edit Presets sheet + per-account presets