feat: add support for Postgres database provider (#79)

backend/migrations/sqlite/20241023072742_unix-timestamps.down.sql

@@ -0,0 +1,28 @@
+-- Convert the Unix timestamps back to DATETIME format
+
+UPDATE user_groups
+SET created_at = datetime(created_at, 'unixepoch');
+
+UPDATE users
+SET created_at = datetime(created_at, 'unixepoch');
+
+UPDATE audit_logs
+SET created_at = datetime(created_at, 'unixepoch');
+
+UPDATE oidc_authorization_codes
+SET created_at = datetime(created_at, 'unixepoch'),
+    expires_at = datetime(expires_at, 'unixepoch');
+
+UPDATE oidc_clients
+SET created_at = datetime(created_at, 'unixepoch');
+
+UPDATE one_time_access_tokens
+SET created_at = datetime(created_at, 'unixepoch'),
+    expires_at = datetime(expires_at, 'unixepoch');
+
+UPDATE webauthn_credentials
+SET created_at = datetime(created_at, 'unixepoch');
+
+UPDATE webauthn_sessions
+SET created_at = datetime(created_at, 'unixepoch'),
+    expires_at = datetime(expires_at, 'unixepoch');