Cardano Updates

- Derive Mithril and chain-storage tokens from each runtime theme.

- Derive weight combined download progress by actual transfer sizes.

- Refresh selector styles and add missing font and spinner imports.

Upgrade cardano-node from 10.6.2 to 10.7.1 and configure the V2LSM
ledger backend to reduce memory usage by storing UTxO data on disk
rather than in-heap. Also updates the cardano-playground config pin
and switches the config path to environments-pre/.

docs(readme): add license badge

Fix chain storage path handling and enhance validation

- reject nested managed-chain selections and default-path symlink aliases
- require cardano-node to be fully stopped before destructive storage changes
- prevent selfnode config failures from mutating chain storage
- make Mithril status delivery resilient to renderer failures and window recreation
- preserve invalid picker paths, surface apply/reset failures, and serialize return-to-storage cleanup
- clear transient Mithril state on preparing/cancelled and document the review-driven fixes

Daedalus 7.3.0

Use jq to patch the generated config.yaml so ConsensusMode is set to
PraosMode, overriding whatever the upstream cardano-playground provides.