Add production plan release checklist

backend/db.js

@@ -189,6 +189,21 @@ const initDB = async () => {
             );
         `);
 
+        // The release decision remains auditable when the plan changes status.
+        await pool.query(`
+            CREATE TABLE IF NOT EXISTS production_plan_reviews (
+                id SERIAL PRIMARY KEY,
+                production_plan_id INTEGER NOT NULL UNIQUE REFERENCES production_plans(id) ON DELETE CASCADE,
+                decision VARCHAR(30) NOT NULL DEFAULT 'pending',
+                checklist JSONB NOT NULL DEFAULT '{}'::jsonb,
+                notes TEXT,
+                reviewed_by TEXT,
+                reviewed_at TIMESTAMPTZ,
+                created_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
+                updated_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP
+            );
+        `);
+
         await pool.query(`
             ALTER TABLE production_orders
             ADD COLUMN IF NOT EXISTS production_plan_id INTEGER REFERENCES production_plans(id) ON DELETE SET NULL,