- Add sync.RWMutex to ConsistentHashRing struct
- Use Lock/Unlock for write operations (AddNode, RemoveNode)
- Use RLock/RUnlock for read operations (GetNode, GetNodes, IsEmpty)
This allows concurrent reads (the common case) while serializing writes,
preventing race conditions when multiple goroutines access the hash ring.
Closes#35
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add config structs with sensible defaults for tunable parameters:
- JetStreamConfig for stream retention (1 year) and replica count (1)
- HashRingConfig for virtual nodes per physical node (150)
- ShardConfig for shard count (1024) and replication factor (1)
Each component gets a new WithConfig constructor that accepts custom
configuration, while the original constructors continue to work with
defaults. Zero values in configs fall back to defaults for backward
compatibility.
Closes#38
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>