refactor: ♻️ new limits for database varchars

migrations/20241204225143_create_post_table.up.sql

@@ -2,5 +2,5 @@
 CREATE TABLE IF NOT EXISTS "post"(
     creation_time TIMESTAMPTZ PRIMARY KEY UNIQUE NOT NULL DEFAULT NOW(),
     user_id BIGSERIAL NOT NULL REFERENCES "user"(id),
-    post VARCHAR NOT NULL UNIQUE
+    post VARCHAR(8192) NOT NULL UNIQUE
 );