feat(appchain): add reusable EUTxO state machine and Cardano settlement

[satran004]

Summary

• add the reusable Cardano-shaped EUTxO ledger and client/testkit modules
• add bounded key-payment and Plutus V3 execution profiles
• add stable Cardano deposit observation and federated withdrawal coordination
• add proof-gated settlement contracts and operational safety boundaries
• deliver and test milestones UTXO-M1 through UTXO-M5

Scope

This is the Phase A/B integration PR. ZK validity-rollup support is intentionally delivered in a separate stacked PR.

Validation

• module unit and integration suites
• deterministic replay, restart, snapshot, and MPF proof coverage
• bridge deposit, withdrawal, recovery, and proof-settlement tests
• packaged JVM/plugin boundary checks