implement bare basic functionality!!!

crates/backend/migrations/20240921175315_init.sql

@@ -10,8 +10,10 @@ create table chats (
 
 create table messages (
     id uuid default (gen_random_uuid()) primary key,
-    timestamp timestamptz default (now()),
+    timestamp timestamptz not null default (now()),
     chat_id uuid not null references chats(id),
     content varchar(2000) not null,
     from_admin boolean not null
-)
+);
+
+insert into chats (url_path) values ('tstcht');