Add audited Graphs stock balances

backend/db.js

@@ -97,6 +97,35 @@ const initDB = async () => {
             ALTER COLUMN updated_at SET DEFAULT CURRENT_TIMESTAMP;
         `).catch(() => {});
 
+        // Tiny/Olist remains the imported source balance. Graphs physical balances
+        // are stored separately so planning can use a verified count without
+        // overwriting the audit value received from Tiny.
+        await pool.query(`
+            CREATE TABLE IF NOT EXISTS stock_graphs_balances (
+                produto_id VARCHAR(100) PRIMARY KEY,
+                balance NUMERIC(14, 4) NOT NULL,
+                reason TEXT NOT NULL,
+                effective_at DATE,
+                updated_by VARCHAR(255),
+                created_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
+                updated_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP
+            );
+        `);
+
+        await pool.query(`
+            CREATE TABLE IF NOT EXISTS stock_graphs_balance_history (
+                id SERIAL PRIMARY KEY,
+                produto_id VARCHAR(100) NOT NULL,
+                tiny_balance NUMERIC(14, 4),
+                graphs_balance NUMERIC(14, 4),
+                reason TEXT,
+                effective_at DATE,
+                action VARCHAR(20) NOT NULL DEFAULT 'set',
+                changed_by VARCHAR(255),
+                created_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP
+            );
+        `);
+
         await pool.query(`
             CREATE TABLE IF NOT EXISTS stock_campaign_queue (
                 id SERIAL PRIMARY KEY,
@@ -675,6 +704,7 @@ const initDB = async () => {
         });
 
         await pool.query(`CREATE INDEX IF NOT EXISTS idx_stock_campaign_queue_status ON stock_campaign_queue (status);`);
+        await pool.query(`CREATE INDEX IF NOT EXISTS idx_stock_graphs_balance_history_product_created ON stock_graphs_balance_history (produto_id, created_at DESC);`);
         await pool.query(`CREATE INDEX IF NOT EXISTS idx_production_orders_status ON production_orders (status);`);
         await pool.query(`CREATE INDEX IF NOT EXISTS idx_production_orders_issue_date ON production_orders (issue_date DESC);`);
         await pool.query(`CREATE INDEX IF NOT EXISTS idx_production_orders_expected_date ON production_orders (expected_date DESC);`);