Updated sinks to add a functional postgres sink API.

README.md

@@ -97,8 +97,13 @@ Compiles routes and fans out events to sinks with per-sink queue/worker isolatio
 
 ### `sinks`
 
-Defines sink interface and sink registry. Built-ins include `stdout` and `nats`, with
-additional sink implementations at varying maturity.
+Defines sink interface and sink registry. Built-ins include:
+- `stdout`
+- `nats`
+- `postgres` (downstream registers table schema + event mapper; feedkit handles create-if-missing DDL, transactional inserts, and optional prune APIs)
+
+Detailed Postgres configuration and wiring examples live in package docs:
+`sinks/doc.go`.
 
 ## Typical wiring