fix(pools): correct CallContract API usage in pool discovery

- Update go.mod to Go 1.21 (from invalid 1.25)
- Add missing dependencies: gorilla/websocket, stretchr/testify
- Fix CallContract calls to use ethereum.CallMsg instead of map
- Import ethereum package for CallMsg type

These fixes resolve compilation errors in the pool discovery
service that would prevent the application from building.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

pkg/pools/discovery.go

@@ -7,7 +7,7 @@ import (
 	"math/big"
 	"sync"
 
-	"github.com/ethereum/go-ethereum/accounts/abi/bind"
+	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/ethclient"
 
@@ -202,9 +202,9 @@ func (d *Discovery) getUniswapV2Pool(ctx context.Context, factory common.Address
 	calldata := append([]byte{0xe6, 0xa4, 0x39, 0x05}, // getPair selector
 		append(padLeft(token0.Bytes(), 32), padLeft(token1.Bytes(), 32)...)...)
 
-	result, err := d.client.CallContract(ctx, map[string]interface{}{
-		"to":   factory,
-		"data": common.Bytes2Hex(calldata),
+	result, err := d.client.CallContract(ctx, ethereum.CallMsg{
+		To:   &factory,
+		Data: calldata,
 	}, nil)
 	if err != nil {
 		return common.Address{}, err
@@ -223,9 +223,9 @@ func (d *Discovery) fetchUniswapV2PoolInfo(ctx context.Context, poolAddr, token0
 	// Simplified - in production use generated bindings
 	calldata := []byte{0x09, 0x02, 0xf1, 0xac} // getReserves selector
 
-	result, err := d.client.CallContract(ctx, map[string]interface{}{
-		"to":   poolAddr,
-		"data": common.Bytes2Hex(calldata),
+	result, err := d.client.CallContract(ctx, ethereum.CallMsg{
+		To:   &poolAddr,
+		Data: calldata,
 	}, nil)
 	if err != nil {
 		return nil, err
@@ -328,9 +328,10 @@ func (d *Discovery) getUniswapV3Pool(ctx context.Context, token0, token1 common.
 	calldata := append([]byte{0x17, 0x79, 0x05, 0x7a}, // getPool selector
 		append(append(padLeft(token0.Bytes(), 32), padLeft(token1.Bytes(), 32)...), feeBytes...)...)
 
-	result, err := d.client.CallContract(ctx, map[string]interface{}{
-		"to":   UniswapV3FactoryAddress,
-		"data": common.Bytes2Hex(calldata),
+	factoryAddr := UniswapV3FactoryAddress
+	result, err := d.client.CallContract(ctx, ethereum.CallMsg{
+		To:   &factoryAddr,
+		Data: calldata,
 	}, nil)
 	if err != nil {
 		return common.Address{}, err
@@ -349,9 +350,9 @@ func (d *Discovery) fetchUniswapV3PoolInfo(ctx context.Context, poolAddr, token0
 	// Simplified - in production use generated bindings
 	calldata := []byte{0x1a, 0x68, 0x65, 0x02} // liquidity selector
 
-	result, err := d.client.CallContract(ctx, map[string]interface{}{
-		"to":   poolAddr,
-		"data": common.Bytes2Hex(calldata),
+	result, err := d.client.CallContract(ctx, ethereum.CallMsg{
+		To:   &poolAddr,
+		Data: calldata,
 	}, nil)
 	if err != nil {
 		return nil, err