fix(shell): support UNC paths in Windows path extraction

- Update regex in _extract_absolute_paths to match both drive paths (C:\...) and UNC paths (\server\share)
- Add comprehensive test cases for UNC paths, mixed paths, and edge cases

nanobot/agent/tools/shell.py

@@ -413,9 +413,12 @@ class ExecTool(Tool):
 
     @staticmethod
     def _extract_absolute_paths(command: str) -> list[str]:
-        # Windows: match drive-root paths like `C:\` as well as `C:\path\to\file`
+        # Windows: match drive-root paths like `C:\` as well as `C:\path\to\file`, and UNC paths like `\\server\share`
         # NOTE: `*` is required so `C:\` (nothing after the slash) is still extracted.
-        win_paths = re.findall(r"[A-Za-z]:\\[^\s\"'|><;]*", command)
+        win_paths = re.findall(
+            r"(?:[A-Za-z]:[^\s\"'|><;]*|\\\\[^\s\"'|><;]+(?:\\[^\s\"'|><;]+)*)",
+            command
+        )
         posix_paths = re.findall(r"(?:^|[\s|>'\"])(/[^\s\"'>;|<]+)", command) # POSIX: /absolute only
         home_paths = re.findall(r"(?:^|[\s>'\"])(~[^\s\"'>;|<]*)", command) # POSIX/Windows home shortcut: ~
         return win_paths + posix_paths + home_paths