fix: update provider status, models, error handling, and imports

- Set `working = False` in Free2GPT, Startnest, and Reka providers
- Changed `default_model` in LambdaChat from `deepseek-v3-0324` to `deepseek-r1`
- Removed `deepseek-v3` alias from LambdaChat's `model_aliases`
- In Kimi provider:
  - Replaced manual status check with `await raise_for_status(response)`
  - Set `model` field to `"k2"` in chat completion request
  - Removed unused `pass` statement
- In WeWordle provider:
  - Removed `**kwargs` from `data_payload` construction
- In Reka provider:
  - Set default value for `stream` to `True`
  - Modified `get_cookies` call to use `cache_result=False`
- In `cli/client.py`:
  - Added conditional import for `MarkItDown` with `has_markitdown` flag
  - Raised `MissingRequirementsError` if `MarkItDown` is not installed
- In `gui/server/backend_api.py`:
  - Imported `MissingAuthError`
  - Wrapped `get_provider_models` call in try-except block to return 401 if `MissingAuthError` is raised

g4f/cli/client.py

@@ -16,7 +16,12 @@ from g4f.Provider import ProviderUtils
 from g4f.image import extract_data_uri, is_accepted_format
 from g4f.image.copy_images import get_media_dir
 from g4f.client.helper import filter_markdown
-from g4f.integration.markitdown import MarkItDown
+from g4f.errors import MissingRequirementsError
+try:
+    from g4f.integration.markitdown import MarkItDown
+    has_markitdown = True
+except ImportError:
+    has_markitdown = False
 from g4f.config import CONFIG_DIR, COOKIES_DIR
 from g4f import debug
 
@@ -284,6 +289,8 @@ def run_client_args(args):
                 media.append(input_value)
             else:
                 try:
+                    if not has_markitdown:
+                        raise MissingRequirementsError("MarkItDown is not installed. Install it with `pip install -U markitdown`.")
                     md = MarkItDown()
                     text_content = md.convert_url(input_value).text_content
                     input_text += f"\n```\n{text_content}\n\nSource: {input_value}\n```\n"