refactor: sessions table stores token hash instead of plaintext

migrations/001_init.sql

@@ -12,10 +12,11 @@ CREATE UNIQUE INDEX IF NOT EXISTS idx_one_admin ON users(role) WHERE role = 'adm
 CREATE TABLE IF NOT EXISTS sessions (
     id SERIAL PRIMARY KEY,
     user_id INT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
-    token VARCHAR(255) UNIQUE NOT NULL,
+    token_hash CHAR(64) UNIQUE NOT NULL,
+    user_agent VARCHAR(500),
     expires_at TIMESTAMPTZ NOT NULL,
     created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
 );
 
-CREATE INDEX IF NOT EXISTS idx_sessions_token ON sessions(token);
+CREATE INDEX IF NOT EXISTS idx_sessions_token_hash ON sessions(token_hash);
 CREATE INDEX IF NOT EXISTS idx_sessions_expires ON sessions(expires_at);