Module follower_read 

Follower-read decision gate.

FollowerReadGate answers a single question: “given the session’s ReadConsistency and the local node’s role + closed timestamp for the target Raft group, can this read be served locally without forwarding to the leader?”

Decision table

Consistency	Local role	Closed TS fresh?	Serve locally?
Strong	*	*	Only if leader
BoundedStaleness(d)	Follower	≤ d	Yes
BoundedStaleness(d)	Follower	> d	No → forward
BoundedStaleness(d)	Leader	*	Yes
Eventual	*	*	Yes

The gate is stateless — it reads from shared handles to the closed-timestamp tracker and the raft-status provider.

Structs

FollowerReadGate

Answers “can this read be served locally?”

Enums

ReadLevel

Consistency level for a single read — mirrors the ReadConsistency enum in the nodedb crate without coupling nodedb-cluster to it.