Split core block SQL rows

[yvette-carlisle]

Summary

• Move internal core block SQL row carriers from core_blocks/types.rs into core_blocks/rows.rs.
• Keep rows private to the core_blocks module and scoped with pub(in crate::core_blocks).
• Preserve the public core_blocks API re-exports and leave public DTOs/prepared request types in types.rs.

Validation

• cargo make fmt-rust
• cargo make check-rust
• cargo make lint-vstyle
• cargo make lint-rust
• cargo make test-rust
• cargo make check
• cargo make test-rust-integration
• cargo make check-trace-gate
• git diff --cached --check