feat: minor changes to db and new query

sql/migrations/000001_init.up.sql

@@ -44,6 +44,7 @@ CREATE TABLE studios (
 
 CREATE TABLE titles (
     id                  bigint              GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
+    -- example {"ru": ["Атака титанов", "Атака Титанов"],"en": ["Attack on Titan", "AoT"],"ja": ["進撃の巨人", "しんげきのきょじん"]}
     title_names         jsonb               NOT NULL,
     studio_id           bigint              NOT NULL REFERENCES studios (id),
     poster_id           bigint              REFERENCES images (id),
@@ -55,6 +56,7 @@ CREATE TABLE titles (
     season              int                 CHECK (season >= 0),
     episodes_aired      int                 CHECK (episodes_aired >= 0),
     episodes_all        int                 CHECK (episodes_all >= 0),
+    -- example { "1": "50.50", "2": "23.23"}
     episodes_len        jsonb,
     CHECK ((episodes_aired IS NULL AND episodes_all IS NULL)
         OR (episodes_aired IS NOT NULL AND episodes_all IS NOT NULL 
@@ -86,7 +88,7 @@ CREATE TABLE signals (
 );
 
 CREATE TABLE external_ids (
-    user_id                                 NOT NULL REFERENCES users (id),
+    user_id             bigint              NOT NULL REFERENCES users (id),
     service_id          bigint              REFERENCES external_services (id),
     external_id         text                NOT NULL
 );