providers/compatible: gate tool_stream on requires_tool_stream() in streaming paths

- stream_chat_with_tools 两个分支无条件发 tool_stream: Some(true)，非 Z.AI
  provider 报 400
- 两处都改成 tool_stream_for_tools() 门控，与非流式路径一致
- 加 non_zai_provider_omits_tool_stream 回归测试

Ports upstream 1da35db (zeroclaw-labs#5806) to master_wecom's
pre-workspace-split layout.

Co-authored-by: Eugene Zavertiaev <152089142+zavertiaev@users.noreply.github.com>

Author: whtiehack

src/providers/compatible.rs

@@ -2067,7 +2067,11 @@ impl Provider for OpenAiCompatibleProvider {
                 ),
                 temperature,
                 reasoning_effort: self.reasoning_effort.clone(),
-                tool_stream: if options.enabled { Some(true) } else { None },
+                tool_stream: if options.enabled {
+                    self.tool_stream_for_tools(true)
+                } else {
+                    None
+                },
                 stream: Some(options.enabled),
                 tools: tools.clone(),
                 tool_choice: tools.as_ref().map(|_| "auto".to_string()),
@@ -2091,7 +2095,11 @@ impl Provider for OpenAiCompatibleProvider {
                 messages,
                 temperature,
                 reasoning_effort: self.reasoning_effort.clone(),
-                tool_stream: if options.enabled { Some(true) } else { None },
+                tool_stream: if options.enabled {
+                    self.tool_stream_for_tools(false)
+                } else {
+                    None
+                },
                 stream: Some(options.enabled),
                 tools: None,
                 tool_choice: None,

src/providers/compatible/tests.rs

@@ -1039,6 +1039,13 @@ fn z_ai_host_enables_tool_stream_for_custom_profiles() {
     assert_eq!(provider.tool_stream_for_tools(true), Some(true));
 }
 
+#[test]
+fn non_zai_provider_omits_tool_stream_regardless_of_streaming() {
+    let provider = make_provider("custom", "https://proxy.example.com/v1", None);
+    assert_eq!(provider.tool_stream_for_tools(true), None);
+    assert_eq!(provider.tool_stream_for_tools(false), None);
+}
+
 #[test]
 fn response_with_tool_calls_deserializes() {
     let json = r#"{