feat(solana/dflow): nested swap render (Swap Details / Route / Accounts)

[prasanna-anchorage]

What

Renders the DFlow Aggregator swap instruction as a nested preview_layout: a condensed at-a-glance summary that expands into three collapsible cards.

• Condensed: Program, Instruction, Route, Quoted Out Amount, Slippage, Platform Fee
• Expanded:
  • Swap Details -- economics + Program ID + Discriminator
  • Route -- per-action breakdown; single-field actions (e.g. RecordId) collapse to a plain field
  • Accounts -- IDL-resolved accounts shown by address (const-seed PDAs derived offline), plus an Unresolved (lookup table) index list for ALT-loaded accounts the parser can't resolve offline

Follows the inner-program nesting convention used by the swig/squads visualizers.

Stacking

• Base: fix(visualsign): render number fields as amount_v2 (VSP has no number type) #393 (number -> amount_v2). The swap economics render via the preset's own number_text helper, so they appear as text_v2.
• Until fix(solana/dflow): collapse arg flattening into one charset-safe field per arg #387 (charset-safe arg collapse) lands on main, this diff also shows fix(solana/dflow): collapse arg flattening into one charset-safe field per arg #387's charset_safe changes to the same file. Once fix(solana/dflow): collapse arg flattening into one charset-safe field per arg #387 + fix(visualsign): render number fields as amount_v2 (VSP has no number type) #393 merge, this will be retargeted to main and shed those.
• Discriminator surfacing is covered by the gate in test(solana): gate that IDL presets surface the instruction discriminator #391.

Render decision

Going with the nested design first (confirmed after reviewing in the VSP playground). The open question is whether the production Anchorage VSPModalReducer drills into a nested preview_layout; a flat fallback (section-header rows, all detail in one Expanded) is drafted and revertible if iOS confirms it can't. Kept as a draft until that's settled.

Follow-ups

• Solana: wallet-provided token metadata channel for swap visualizers (mirror Ethereum) #388 -- Solana wallet token-metadata channel (ALT-resolved mint symbols/decimals)

🤖 Generated with Claude Code