fix(anthropic): skip tool calls with empty names to prevent API errors (#1739)

When building parameters for Anthropic API calls, tool calls with empty
names would cause 400 Bad Request errors with the message:
'tool_use.name: String should have at least 1 character'

This fix adds a check to skip tool calls that have empty names, preventing
the API error and allowing the conversation to continue normally.

Fixes #1658

pkg/providers/anthropic/provider.go

@@ -180,6 +180,10 @@ func buildParams(
 					blocks = append(blocks, anthropic.NewTextBlock(msg.Content))
 				}
 				for _, tc := range msg.ToolCalls {
+					// Skip tool calls with empty names to avoid API errors
+					if tc.Name == "" {
+						continue
+					}
 					args := tc.Arguments
 					if args == nil && tc.Function != nil && tc.Function.Arguments != "" {
 						if err := json.Unmarshal([]byte(tc.Function.Arguments), &args); err != nil {