Adds the opt-in flags needed to bring the studio-canonical
"Entry/Action confirmed" look (large title, branded tx receipt, CTA
with drain-bar countdown, optional product-specific extras below)
behind one shared partial. Lets consumers consolidate web2 and web3
success cards onto the same block.

### Added
- `large_title:` boolean — text-3xl headline (vs default text-lg).
- `title_key:` / `message_key:` — Alpine-expression locals for live-
  driven copy that updates as a store mutates without re-mounting
  the card (matches the same option on _processing_card from v0.4.6).
- `tx_solana:` boolean — upgrades the tx_signature_key link from
  plain underlined hash to a boxed pill with the Solana brand mark
  (gradient SVG) + launch arrow.
- `cta_drain:` boolean — when paired with auto_redirect_url_key, the
  countdown drains as a translucent overlay on the CTA button. No
  separate progress bar or "Redirecting in Xs…" text. The
  celebration look.
- Yield block — callers can pass an inline block that renders below
  the CTA, used for product-specific celebration extras (e.g.
  turf-monster's seeds bar + level-up animation) without forking
  the partial.
- @keyframes studio-modal-drain in the host's style block, drives
  the cta_drain animation.

All additive. Existing callers unaffected.