preserve tool definition and call JSON ordering (#13525)

* preserve tool definition and call JSON ordering

This is another iteration of
<https://github.com/ollama/ollama/pull/12518>, but this time we've
simplified things by relaxing the competing requirements of being
compatible AND order-preserving with templates (vs. renderers). We
maintain backwards compatibility at the cost of not guaranteeing order
for templates. We plan on moving more and more models to renderers,
which have been updated to use these new data types, and additionally
we could add an opt-in way of templates getting an order-preserved list
(e.g., via sibling template vars)

* orderedmap_test: remove testify

template/template.go

@@ -272,8 +272,8 @@ func (t *Template) Execute(w io.Writer, v Values) error {
 	} else if !v.forceLegacy && slices.Contains(vars, "messages") {
 		return t.Template.Execute(w, map[string]any{
 			"System":     system,
-			"Messages":   messages,
-			"Tools":      v.Tools,
+			"Messages":   convertMessagesForTemplate(messages),
+			"Tools":      convertToolsForTemplate(v.Tools),
 			"Response":   "",
 			"Think":      v.Think,
 			"ThinkLevel": v.ThinkLevel,
@@ -373,6 +373,118 @@ func collate(msgs []api.Message) (string, []*api.Message) {
 	return strings.Join(system, "\n\n"), collated
 }
 
+// templateTools is a slice of templateTool that marshals to JSON.
+type templateTools []templateTool
+
+func (t templateTools) String() string {
+	bts, _ := json.Marshal(t)
+	return string(bts)
+}
+
+// templateTool is a template-compatible representation of api.Tool
+// with Properties as a regular map for template ranging.
+type templateTool struct {
+	Type     string               `json:"type"`
+	Items    any                  `json:"items,omitempty"`
+	Function templateToolFunction `json:"function"`
+}
+
+type templateToolFunction struct {
+	Name        string                         `json:"name"`
+	Description string                         `json:"description"`
+	Parameters  templateToolFunctionParameters `json:"parameters"`
+}
+
+type templateToolFunctionParameters struct {
+	Type       string                      `json:"type"`
+	Defs       any                         `json:"$defs,omitempty"`
+	Items      any                         `json:"items,omitempty"`
+	Required   []string                    `json:"required,omitempty"`
+	Properties map[string]api.ToolProperty `json:"properties"`
+}
+
+// templateToolCall is a template-compatible representation of api.ToolCall
+// with Arguments as a regular map for template ranging.
+type templateToolCall struct {
+	ID       string
+	Function templateToolCallFunction
+}
+
+type templateToolCallFunction struct {
+	Index     int
+	Name      string
+	Arguments map[string]any
+}
+
+// templateMessage is a template-compatible representation of api.Message
+// with ToolCalls converted for template use.
+type templateMessage struct {
+	Role       string
+	Content    string
+	Thinking   string
+	Images     []api.ImageData
+	ToolCalls  []templateToolCall
+	ToolName   string
+	ToolCallID string
+}
+
+// convertToolsForTemplate converts Tools to template-compatible format.
+func convertToolsForTemplate(tools api.Tools) templateTools {
+	if tools == nil {
+		return nil
+	}
+	result := make(templateTools, len(tools))
+	for i, tool := range tools {
+		result[i] = templateTool{
+			Type:  tool.Type,
+			Items: tool.Items,
+			Function: templateToolFunction{
+				Name:        tool.Function.Name,
+				Description: tool.Function.Description,
+				Parameters: templateToolFunctionParameters{
+					Type:       tool.Function.Parameters.Type,
+					Defs:       tool.Function.Parameters.Defs,
+					Items:      tool.Function.Parameters.Items,
+					Required:   tool.Function.Parameters.Required,
+					Properties: tool.Function.Parameters.Properties.ToMap(),
+				},
+			},
+		}
+	}
+	return result
+}
+
+// convertMessagesForTemplate converts Messages to template-compatible format.
+func convertMessagesForTemplate(messages []*api.Message) []*templateMessage {
+	if messages == nil {
+		return nil
+	}
+	result := make([]*templateMessage, len(messages))
+	for i, msg := range messages {
+		var toolCalls []templateToolCall
+		for _, tc := range msg.ToolCalls {
+			toolCalls = append(toolCalls, templateToolCall{
+				ID: tc.ID,
+				Function: templateToolCallFunction{
+					Index:     tc.Function.Index,
+					Name:      tc.Function.Name,
+					Arguments: tc.Function.Arguments.ToMap(),
+				},
+			})
+		}
+		result[i] = &templateMessage{
+			Role:       msg.Role,
+			Content:    msg.Content,
+			Thinking:   msg.Thinking,
+			Images:     msg.Images,
+			ToolCalls:  toolCalls,
+			ToolName:   msg.ToolName,
+			ToolCallID: msg.ToolCallID,
+		}
+	}
+	return result
+}
+
 // Identifiers walks the node tree returning any identifiers it finds along the way
 func Identifiers(n parse.Node) ([]string, error) {
 	switch n := n.(type) {