aider: The cmd_add method in the Commands class has been modified to allow the /add command to accept glob patterns.

# Context:
USER: Feature Description
Currently, the /add function accepts directory paths to add the entire directory or spefic file paths to the program's context. A useful enhancement would be to support the use of regex or glob expressions with the /add function. This would give users more flexibility and control to specify exactly which files to include.

Proposed Solution
Allow the /add function to interpret glob or regex patterns. For example, a user could use /add src/*.py to include only Python files from the src directory or /add src/[A-C]* to add only files that start with A, B, or C.

Expected Behavior
When a user runs /add with a regex or glob pattern, the program should add to the context only the files that match the pattern. The program should handle non-matching files or non-existent paths gracefully, preferably by ignoring them and printing a warning message.

Alternatives Considered
An alternative could be providing an additional function, say /addPattern, that accepts regex/glob patterns. This approach would leave the existing /add functionality unchanged for users who don't need the enhanced functionality.

Additional Context
Adding this feature would boost the flexibility of the /add function, making the program more convenient to use for a variety of tasks. Users could, for instance, exclude certain types of files or select a subset of files based on their naming conventions.
ASSISTANT: To implement this feature, we need to modify the `cmd_add` method in the `Commands` class in the `aider/commands.py` file.

The changes will involve:
1. Interpreting the input argument as a glob pattern.
2. Using the `glob` module to find all files that match the pattern.
3. Adding the matched files to the chat session.

Here is the proposed change:

```python
aider/commands.py
<<<<<<< ORIGINAL
    def cmd_add(self, args):
        "Add matching files to the chat session"

        added_fnames = []
        files = self.coder.get_all_relative_files()
        for word in args.split():
            matched_files = [file for file in files if word in file]
=======
    import glob

    def cmd_add(self, args):
        "Add matching files to the chat session using glob patterns"

        added_fnames = []
        for pattern in args.split():
            matched_files = glob.glob(pattern, recursive=True)
>>>>>>> UPDATED
```

This change will allow the `/add` command to accept glob patterns. For example, `/add src/*.py` will add all Python files in the `src` directory to the chat session.

aider/commands.py

@@ -216,13 +216,14 @@ class Commands:
             if partial.lower() in fname.lower():
                 yield Completion(fname, start_position=-len(partial))
 
+    import glob
+
     def cmd_add(self, args):
-        "Add matching files to the chat session"
+        "Add matching files to the chat session using glob patterns"
 
         added_fnames = []
-        files = self.coder.get_all_relative_files()
-        for word in args.split():
-            matched_files = [file for file in files if word in file]
+        for pattern in args.split():
+            matched_files = glob.glob(pattern, recursive=True)
 
             if not matched_files:
                 if self.coder.repo is not None: