Fix clippy warnings blocking CI (plan §7 requires -D warnings to pass):
- multi_search.rs: fix format strings, field initialization, unused variables
- anti_entropy_worker.rs: make ModeACoordinator public, prefix unused fields with _, allow dead code for future-use methods
- cdc.rs: allow unused fields and variables (intentionally kept for future use), rename from_str to parse_from_str to avoid std trait confusion
- scatter.rs, mode_b_coordinator.rs, group_sync_worker.rs, mode_a_coordinator.rs: move or remove unused imports
- alias/acceptance_tests.rs, mode_b_acceptance_tests.rs: remove unused imports
These changes fix the initial clippy errors while preserving intentionally-unused code for future use (marked with #[allow(dead_code)] or underscore prefixes).
Closes: bf-ed5n
1f894b4dc2