fix(coordinator): choose highest term and entry node as leader

[mattisonchao]

Motivation

Follow the TLA+. We should choose the highest term entry node as the leader, which can also fix the issue we encountered.

• The leader can't truncate the following because of the protection logic.

{"level":"info","time":"2024-11-14T01:04:55.195566194Z","component":"shard-controller","namespace":"xxx","shard":10,"term":278,"time":"2024-11-14T01:04:55.195588258Z","message":"Starting leader election"}
{"level":"info","time":"2024-11-14T01:04:55.218118449Z","component":"shard-controller","entry-id":{"term":"78","offset":"5652112"},"namespace":"xxx","server-address":{"public":"xxxxxxx:6648","internal":"xxxxxxx:6649"},"shard":10,"time":"2024-11-14T01:04:55.218152924Z","message":"Processed newTerm response"}
{"level":"info","time":"2024-11-14T01:04:55.218347701Z","component":"shard-controller","entry-id":{"term":"78","offset":"5652112"},"namespace":"xxx","server-address":{"public":"xxxxxxx:6648","internal":"xxxxxxx:6649"},"shard":10,"time":"2024-11-14T01:04:55.218369944Z","message":"Processed newTerm response"}
{"level":"info","time":"2024-11-14T01:04:55.219517988Z","component":"shard-controller","entry-id":{"term":"77","offset":"5653106"},"namespace":"xxx","server-address":{"public":"xxxxxxx:6648","internal":"xxxxxxx:6649"},"shard":10,"time":"2024-11-14T01:04:55.219534113Z","message":"Processed newTerm response"}
{"level":"info","time":"2024-11-14T01:04:55.219554195Z","component":"shard-controller","followers":[{"server-address":{"public":"xxxxxxx:6648","internal":"xxxxxxx:6649"},"entry-id":{"term":78,"offset":5652112}},{"server-address":{"public":"xxxxxxx:6648","internal":"xxxxxxx:6649"},"entry-id":{"term":78,"offset":5652112}}],"namespace":"xxx","new-leader":{"public":"xxxxxxx:6648","internal":"xxxxxxx:6649"},"shard":10,"term":278,"time":"2024-11-14T01:04:55.219564969Z","message":"Successfully moved ensemble to a new term"}