Inconsistent member_id source between Raft and server config causes identity mismatch

[yantingqiu]

Summary

The Raft node uses the CLI flag --member-id while other components (etcd server, RocksDB path, KV store binding) use [cfg.Server.MemberID] from config/env. This creates a split identity for the same process.

Impact

• Data/metadata mismatch: Raft node ID differs from etcd server’s advertised member_id.
• Storage path divergence: RocksDB path uses config member_id while Raft uses CLI member_id.
• Cluster instability: inconsistent IDs can break peer mapping, joins, and recovery.