implement account management

migrations/20250206105906_initial.sql

@@ -0,0 +1,11 @@
+-- Add migration script here
+CREATE TABLE accounts (account_id VARCHAR(10) PRIMARY KEY);
+
+CREATE TABLE caught_fish (
+    id INTEGER PRIMARY KEY,
+    account_id VARCHAR(10),
+    fish_id INTEGER,
+    FOREIGN KEY (account_id) REFERENCES accounts (account_id) ON DELETE CASCADE ON UPDATE NO ACTION
+);
+
+CREATE INDEX fish_accounts ON caught_fish (account_id);