feat: add strict schema enforcement and strip hallucinated fields from tool call parameters

internal/util/toolcalls_parse.go

@@ -158,6 +158,10 @@ func filterToolCallsDetailed(parsed []ParsedToolCall, availableToolNames []strin
 		}
 		if tc.Input == nil {
 			tc.Input = map[string]any{}
+		} else {
+			// Remove known hallucinated fields often generated by models trying to bridge XML and JSON
+			delete(tc.Input, "_raw")
+			delete(tc.Input, "_xml")
 		}
 		out = append(out, tc)
 	}