feat: Improve OpenAI tool call handling by passing unknown tool calls as content and filtering streamed tool calls by schema.

internal/util/standard_request.go

@@ -8,12 +8,48 @@ type StandardRequest struct {
 	Messages       []any
 	FinalPrompt    string
 	ToolNames      []string
+	ToolChoice     ToolChoicePolicy
 	Stream         bool
 	Thinking       bool
 	Search         bool
 	PassThrough    map[string]any
 }
 
+type ToolChoiceMode string
+
+const (
+	ToolChoiceAuto     ToolChoiceMode = "auto"
+	ToolChoiceNone     ToolChoiceMode = "none"
+	ToolChoiceRequired ToolChoiceMode = "required"
+	ToolChoiceForced   ToolChoiceMode = "forced"
+)
+
+type ToolChoicePolicy struct {
+	Mode       ToolChoiceMode
+	ForcedName string
+	Allowed    map[string]struct{}
+}
+
+func DefaultToolChoicePolicy() ToolChoicePolicy {
+	return ToolChoicePolicy{Mode: ToolChoiceAuto}
+}
+
+func (p ToolChoicePolicy) IsNone() bool {
+	return p.Mode == ToolChoiceNone
+}
+
+func (p ToolChoicePolicy) IsRequired() bool {
+	return p.Mode == ToolChoiceRequired || p.Mode == ToolChoiceForced
+}
+
+func (p ToolChoicePolicy) Allows(name string) bool {
+	if len(p.Allowed) == 0 {
+		return true
+	}
+	_, ok := p.Allowed[name]
+	return ok
+}
+
 func (r StandardRequest) CompletionPayload(sessionID string) map[string]any {
 	payload := map[string]any{
 		"chat_session_id":   sessionID,