fix: /v1/responses endpoint drops tool calls (function_call) in non-streaming mode

Also fixes streaming tool call event type and response status.

Non-streaming:
- ClaudeConverter.toOpenAIResponsesResponse now handles tool_use
  content blocks, emitting function_call output items
- OpenAIConverter.toOpenAIResponsesResponse now handles
  message.tool_calls, emitting function_call output items
- Both set status to 'requires_action' when tool calls are present

Streaming:
- OpenAIConverter uses response.function_call_arguments.delta
  instead of response.custom_tool_call_input.delta
- generateResponseCompleted sets status to 'requires_action'
  when tool calls are tracked in stream state

Fixes #471

src/converters/strategies/ClaudeConverter.js

@@ -1648,22 +1648,42 @@ export class ClaudeConverter extends BaseConverter {
      * Claude响应 -> OpenAI Responses响应
      */
     toOpenAIResponsesResponse(claudeResponse, model) {
-        const content = this.processClaudeResponseContent(claudeResponse.content);
-        const textContent = typeof content === 'string' ? content : JSON.stringify(content);
+        const output = [];
+        const messageContent = [];
+        let hasToolUse = false;
 
-        let output = [];
-        output.push({
+        // Process Claude content blocks, handling both text and tool_use
+        if (Array.isArray(claudeResponse.content)) {
+            for (const block of claudeResponse.content) {
+                if (block.type === 'text' && block.text) {
+                    messageContent.push({
+                        annotations: [],
+                        logprobs: [],
+                        text: block.text,
+                        type: "output_text"
+                    });
+                } else if (block.type === 'tool_use') {
+                    hasToolUse = true;
+                    output.push({
+                        type: "function_call",
+                        id: block.id || `fc_${uuidv4().replace(/-/g, '')}`,
+                        call_id: block.id || `call_${uuidv4().replace(/-/g, '')}`,
+                        name: block.name,
+                        arguments: typeof block.input === 'string' ? block.input : JSON.stringify(block.input || {}),
+                        status: "completed"
+                    });
+                }
+            }
+        }
+
+        // Always include the message output item (even if content is empty)
+        output.unshift({
             type: "message",
             id: `msg_${uuidv4().replace(/-/g, '')}`,
             summary: [],
             role: "assistant",
             status: "completed",
-            content: [{
-                annotations: [],
-                logprobs: [],
-                text: textContent,
-                type: "output_text"
-            }]
+            content: messageContent
         });
 
         return {
@@ -1684,7 +1704,7 @@ export class ClaudeConverter extends BaseConverter {
             reasoning: {},
             safety_identifier: "user-" + uuidv4().replace(/-/g, ''),
             service_tier: "default",
-            status: "completed",
+            status: hasToolUse ? "requires_action" : "completed",
             store: false,
             temperature: 1,
             text: {

src/converters/strategies/OpenAIConverter.js

@@ -1642,11 +1642,29 @@ export class OpenAIConverter extends BaseConverter {
             content: messageContent
         });
 
+        // Handle tool calls (function_call output items)
+        if (message.tool_calls && message.tool_calls.length > 0) {
+            for (const tc of message.tool_calls) {
+                if (tc.type === 'function' && tc.function) {
+                    output.push({
+                        type: 'function_call',
+                        id: tc.id || `fc_${Date.now()}`,
+                        call_id: tc.id || `call_${Date.now()}`,
+                        name: tc.function.name,
+                        arguments: tc.function.arguments || '{}',
+                        status: 'completed'
+                    });
+                }
+            }
+        }
+
+        const hasToolCalls = message.tool_calls && message.tool_calls.length > 0;
+
         return {
             id: openaiResponse.id || `resp_${Date.now()}`,
             object: 'response',
             created_at: openaiResponse.created || Math.floor(Date.now() / 1000),
-            status: choice.finish_reason === 'stop' ? 'completed' : 'in_progress',
+            status: hasToolCalls ? 'requires_action' : (choice.finish_reason === 'stop' ? 'completed' : 'in_progress'),
             model: model || openaiResponse.model || 'unknown',
             output: output,
             usage: openaiResponse.usage ? {
@@ -1736,7 +1754,7 @@ export class OpenAIConverter extends BaseConverter {
                         item_id: toolCall.id || `call_${uuidv4().replace(/-/g, '')}`,
                         output_index: outputIndex,
                         sequence_number: 3,
-                        type: "response.custom_tool_call_input.delta"
+                        type: "response.function_call_arguments.delta"
                     });
                 }
             }

src/providers/openai/openai-responses-core.mjs

@@ -304,7 +304,7 @@ function generateResponseCompleted(requestId, usage) {
       },
       safety_identifier: `user-${uuidv4().replace(/-/g, '')}`, // 随机值
       service_tier: "default",
-      status: "completed",
+      status: (state.toolCalls && state.toolCalls.length > 0) ? "requires_action" : "completed",
       store: false,
       temperature: 1,
       text: {