feat!: unify typed scheme validation

[claudewalden0]

Summary

• route pacs.008 scheme validation through the generated 001.13 model and a shared version-neutral facts boundary
• retain explicit FedNow, SEPA, and CBPR+ policy evaluation while preserving raw envelope, size, and control-character findings
• make generic CLI XML extraction command-private and remove the public scanner-based scheme path
• reject malformed XML in the default CLI validation path and enforce actual FedNow and SEPA transaction cardinality
• prevent nested supplementary transactions from suppressing later scheme value rules
• restore SEPA restricted-Latin coverage for agent and ultimate-party names plus street and town fields
• prepare all seven workspace crates for the coordinated 0.4.0 release

Breaking changes

• removes the public mx20022_validate::schemes::xml_scan module
• consolidates generated-model parse and required-field failures into SCHEME_PARSE for typed pacs.008.001.13 validation

Test plan

• cargo fmt --all -- --check
• cargo check --workspace --all-features
• cargo clippy --workspace --all-features -- -D warnings
• cargo test --workspace --all-features
• RUSTDOCFLAGS='--cfg docsrs -Dwarnings' cargo doc --workspace --all-features --no-deps
• real CLI: malformed XML without --scheme exits 1 with a parse diagnostic
• real CLI: FedNow XML declaring one and carrying two transactions exits 1 with FEDNOW_SINGLE_TX
• real CLI: an older FedNow message with nested supplementary CdtTrfTxInf still reports charge-bearer, currency, and amount-limit findings
• SEPA typed and older-version paths reject actual multi-transaction counts and restricted characters in all restored fields