docs: add quote-to-order tutorial with slippage guidance

docs/cow-protocol/integrate/api.mdx

@@ -21,7 +21,7 @@ The primary API for creating and managing orders on CoW Protocol.
 - `POST /api/v1/orders` - Submit signed orders
 - `GET /api/v1/orders/{uid}` - Get order details
 - `DELETE /api/v1/orders/{uid}` - Cancel orders
-- `GET /api/v1/trades` - Get trade history
+- `GET /api/v2/trades` - Get trade history
 
 ## Quick Start Example
 
@@ -31,29 +31,48 @@ The primary API for creating and managing orders on CoW Protocol.
 curl -X POST "https://api.cow.fi/mainnet/api/v1/quote" \
   -H "Content-Type: application/json" \
   -d '{
-    "sellToken": "0xA0b86a33E6411Ec5d0b9dd2E7dC15A9CAA6C1F8e",
+    "sellToken": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
     "buyToken": "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
-    "sellAmountBeforeFee": "1000000",
+    "sellAmountBeforeFee": "1000000000",
     "kind": "sell",
     "from": "0xYourWalletAddress"
   }'
 ```
 
-### 2. Sign and Submit Order
+### 2. Apply Slippage and Sign Order
+
+:::caution Important
+Before signing, you should apply slippage tolerance to protect against price movements. See the [Quote to Order Tutorial](../tutorials/quote-to-order.mdx) for detailed examples.
+:::
 
 ```javascript
-// After getting a quote, sign the order
+// Apply slippage to the quote before signing
+// For sell orders: reduce buyAmount by slippage (e.g., 0.5%)
+const buyAmountWithSlippage = BigInt(quoteResponse.quote.buyAmount) * 995n / 1000n
+const sellAmount = BigInt(quoteResponse.quote.sellAmount) + BigInt(quoteResponse.quote.feeAmount)
+const feeAmount = BigInt(0)
+
+// Build order for signing
 const order = {
-  ...quoteResponse,
-  signature: await signOrder(quoteResponse, signer),
+  ...quoteResponse.quote,
+  sellAmount: sellAmount.toString(),
+  buyAmount: buyAmountWithSlippage.toString(),
+  feeAmount: feeAmount.toString()
+}
+
+const signature = await signOrder(quoteResponse, signer)
+
+const signedOrder = {
+  ...order,
+  signature: signature,
   signingScheme: "eip712"
 }
 
 // Submit the signed order
 const response = await fetch('https://api.cow.fi/mainnet/api/v1/orders', {
   method: 'POST',
   headers: { 'Content-Type': 'application/json' },
-  body: JSON.stringify(order)
+  body: JSON.stringify(signedOrder)
 })
 
 const orderId = await response.text()
@@ -163,4 +182,5 @@ For complete API documentation including all endpoints, parameters, and response
 - **[Order Book API Reference](/cow-protocol/reference/apis/orderbook)** - Detailed API documentation
 - **[API Explorer](https://api.cow.fi/docs/)** - Interactive documentation
 - **[GitHub Examples](https://github.com/cowprotocol/cow-sdk/tree/main/examples)** - Code examples
-- **[Order Signing Guide](../reference/core/signing_schemes.mdx)** - Cryptographic signing details
+- **[Order Signing Guide](../reference/core/signing_schemes.mdx)** - Cryptographic signing details
+- **[Quote to Order Tutorial](../tutorials/quote-to-order.mdx)** - Complete guide with slippage handling