feat(models): add catalog and filesystem utilities

- Introduce models for managing repository catalog and categories
- Add utilities for directory size and Git status checks
- Enable repository metadata management, validation, and operations

src/repocat/utils/fsutils.py

@@ -0,0 +1,43 @@
+import subprocess
+from pathlib import Path
+
+def get_dir_size(path: Path) -> int:
+    """Returns directory size in bytes."""
+    return sum(f.stat().st_size for f in path.rglob("*") if f.is_file())
+
+def is_git_dirty(path: Path) -> bool:
+    """Returns True if there are uncommitted changes."""
+    try:
+        result = subprocess.run(
+            ["git", "status", "--porcelain"],
+            cwd=path,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.DEVNULL,
+            text=True,
+        )
+        return bool(result.stdout.strip())
+    except Exception:
+        return False
+
+def is_git_unpushed(path: Path) -> bool:
+    """Returns True if there are commits that haven't been pushed to upstream."""
+    try:
+        # Check if upstream exists
+        subprocess.run(
+            ["git", "rev-parse", "--abbrev-ref", "--symbolic-full-name", "@{u}"],
+            cwd=path,
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
+            check=True,
+        )
+
+        result = subprocess.run(
+            ["git", "log", "@{u}..HEAD", "--oneline"],
+            cwd=path,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.DEVNULL,
+            text=True,
+        )
+        return bool(result.stdout.strip())
+    except Exception:
+        return False