refactor: update model mappings, error handling, and file utils

- Changed `generate_commit_message` return to `.strip("`").strip()` in `commit.py`
- Added new model mappings in `PollinationsAI.py`, including `gpt-4.1`, `gpt-4.1-mini`, and `deepseek-r1-distill-*`
- Removed `print` debug statement from `PollinationsAI.py` request payload
- Replaced temp file handling in `MarkItDown.py` with `get_tempfile` utility
- Added `get_tempfile` function to `files.py` for consistent tempfile creation
- Added `gpt-4.1` to `text_models` list in `models.py`
- Added `ModelNotSupportedError` to exception handling in `OpenaiChat.py`
- Updated message content creation to use `to_string()` in `OpenaiChat.py`
- Wrapped `get_model()` in try-except to ignore `ModelNotSupportedError` in `OpenaiChat.py`
- Adjusted `convert` endpoint in `api/__init__.py` to accept optional `provider` param
- Refactored `/api/markitdown` to reuse `convert()` handler in `api/__init__.py

etc/tool/commit.py

@@ -201,7 +201,7 @@ def generate_commit_message(diff_text: str, model: str = DEFAULT_MODEL) -> Optio
                         spinner = None
                     content.append(chunk.choices[0].delta.content)
                     print(chunk.choices[0].delta.content, end="", flush=True)
-            return "".join(content).strip().strip("`")
+            return "".join(content).strip("`").strip()
         except Exception as e:
             # Stop spinner if it's running
             if 'spinner' in locals() and spinner: