Small additive follow-up to v0.4.5 for downstream consolidation work
(turf-monster's solanaModal absorption into the shared modal stack
needed these two affordances).

### Added
- **`props.dismissible: false`** on a modal entry now suppresses
  escape-key + click-outside close. Required for steps that mustn't
  be interrupted mid-action (e.g. on-chain TX while a Phantom
  signature is pending — a stray backdrop click could orphan a signed
  but un-confirmed transaction). Defaults to true (existing behavior).
- **`title_key:` / `message_key:`** locals on `_processing_card` for
  Alpine-expression-driven text that updates as state mutates. Pairs
  with stores whose title/message change live (the on-chain TX flow
  cycles through "Sign Entry" → "Confirming Onchain" → … without
  re-mounting the card).