Initial implementation of db stuffs

Got the migrations and datastructures in. Next step is building db
utility function into the db module or client module

migrations/2026-05-18-182028-0000_create_messages/down.sql

@@ -0,0 +1,3 @@
+-- This file should undo anything in `up.sql`
+DROP TABLE messages;
+DROP TYPE room_id;

migrations/2026-05-18-182028-0000_create_messages/up.sql

@@ -0,0 +1,14 @@
+-- Your SQL goes here
+CREATE TYPE room_id AS (
+    coordinates bigint[],
+    server text
+);
+CREATE TABLE messages (
+    id BIGSERIAL PRIMARY KEY,
+    room room_id NOT NULL,
+    body TEXT NOT NULL,
+    signature TEXT NOT NULL,
+    client_timestamp BIGINT NOT NULL,
+    server_timestamp BIGINT NOT NULL,
+    username user_t NOT NULL
+)