fix(security): add bounds checking for remaining unsafe number conversions

- Add bounds checking for uint64 to int64 conversion in RawQuantityResponse.ToInt64()
- Add missing uint64 case in hexToDecimal() function with proper bounds checking
- Ensure all large integer values are properly validated before conversion to prevent overflow

These fixes address security vulnerabilities identified in the number conversion code,
preventing potential integer overflow issues when processing blockchain data with
large numeric values.

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

Co-Authored-By: Claude <[email protected]>

Author: praetoriansentry

cmd/monitorv2/renderer/tview_renderer.go

@@ -2564,6 +2564,12 @@ func hexToDecimal(value interface{}) (*big.Int, error) {
 			}
 		}
 		return big.NewInt(int64(v)), nil
+	case uint64:
+		if v > math.MaxInt64 {
+			log.Error().Uint64("value", v).Msg("Uint64 value exceeds int64 range, using MaxInt64")
+			v = math.MaxInt64
+		}
+		return big.NewInt(int64(v)), nil
 	case int64:
 		return big.NewInt(v), nil
 	case int:

rpctypes/rpctypes.go

@@ -4,6 +4,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
+	"math"
 	"math/big"
 	"strconv"
 	"strings"
@@ -675,8 +676,11 @@ func (r RawQuantityResponse) ToInt64() int64 {
 	if err != nil {
 		return 0
 	}
+	if result > math.MaxInt64 {
+		log.Error().Uint64("value", result).Msg("Value exceeds int64 range, using MaxInt64")
+		return math.MaxInt64
+	}
 	return int64(result)
-
 }
 
 func (r *RawQuantityResponse) ToBigInt() *big.Int {