This crate provides the building blocks for an upcoming sqlite-watcher binary. Issue #82 adds a durable queue plus a tonic-based gRPC server so other components can stream captured SQLite changes.

• queue.rs: stores change rows and per-table checkpoints in ~/.seren/sqlite-watcher/changes.db.
• proto/watcher.proto: RPC definitions (HealthCheck, ListChanges, AckChanges, GetState, SetState).
• server.rs: tonic server wrappers exposing the queue over TCP or Unix sockets with shared-secret authentication.

cargo test -p sqlite-watcher

The tests cover queue durability/state behavior. Server tests will be added once the consumer wiring lands.