fix(browser): show resolved variables in workflow run log input (#15325)

### What problem does this PR solve?

Browser parsed sys.query from prompts but never called set_input_value,
so node_finished inputs displayed null in the agent orchestration run
log.
Additionally, Browser’s tenant-model path could trigger unsupported
structured-output modes (response_format/tool_choice) for some
OpenAI-compatible providers (notably DeepSeek thinking models), causing
step failures.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

test/unit_test/agent/component/test_browser_use_component.py

@@ -53,9 +53,13 @@ class _FakeCanvas:
         self._refs = refs or {}
 
     def is_reff(self, token):
-        return token in self._refs
+        key = token.strip("{} ")
+        return key in self._refs or token in self._refs
 
     def get_variable_value(self, token):
+        key = token.strip("{} ")
+        if key in self._refs:
+            return self._refs[key]
         return self._refs[token]
 
     def get_tenant_id(self):
@@ -69,6 +73,19 @@ def _build_component():
     return component
 
 
+def test_prepare_input_values_records_variable_inputs():
+    component = browser_use_module.Browser.__new__(browser_use_module.Browser)
+    component._canvas = _FakeCanvas(refs={"sys.query": "open example.com"})
+    component._param = browser_use_module.BrowserParam()
+    component._param.prompts = "{sys.query}"
+    component._param.inputs = {}
+
+    component._prepare_input_values()
+
+    assert component.get_input_value("sys.query") == "open example.com"
+    assert component.get_input_values()["sys.query"] == "open example.com"
+
+
 def test_extract_ids_supports_mixed_literals_and_variables():
     component = browser_use_module.Browser.__new__(browser_use_module.Browser)
     component._canvas = _FakeCanvas(