Fix status: exclude .dvc directory from file glob

The glob '**/*.dvc' was matching the .dvc directory itself
in addition to .dvc files. Added is_file() filter.

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: Ubuntu

dvx/commands/status.py

@@ -60,7 +60,8 @@ def run(self):
         targets = list(args.targets) if args.targets else []
         if not targets:
             # Default: find all .dvc files recursively (like git status)
-            targets = list(Path('.').glob('**/*.dvc'))
+            # Filter to files only (exclude .dvc directory itself)
+            targets = [p for p in Path('.').glob('**/*.dvc') if p.is_file()]
             if not targets:
                 logger.warning("No .dvc files found")
                 return 0