feat(shared): add config and filesystem utilities

backend/app/shared/infrastructure/config.py

@@ -0,0 +1,9 @@
+from dataclasses import dataclass, field
+from pathlib import Path
+
+
+@dataclass
+class Settings:
+    registry_path: Path = field(
+        default_factory=lambda: Path.home() / ".arch-design-dashboard" / "projects.json"
+    )

backend/app/shared/infrastructure/filesystem.py

@@ -0,0 +1,33 @@
+from pathlib import Path
+
+from app.shared.kernel.exceptions import FileSystemError
+
+
+def read_text(path: Path) -> str:
+    try:
+        return path.read_text(encoding="utf-8")
+    except OSError as e:
+        raise FileSystemError(str(path), str(e)) from e
+
+
+def write_text(path: Path, content: str) -> None:
+    try:
+        path.parent.mkdir(parents=True, exist_ok=True)
+        path.write_text(content, encoding="utf-8")
+    except OSError as e:
+        raise FileSystemError(str(path), str(e)) from e
+
+
+def list_files(directory: Path, extensions: list[str] | None = None) -> list[Path]:
+    if not directory.is_dir():
+        raise FileSystemError(str(directory), "Not a directory")
+    files: list[Path] = []
+    for p in sorted(directory.rglob("*")):
+        if p.is_file():
+            if extensions is None or p.suffix in extensions:
+                files.append(p)
+    return files
+
+
+def file_exists(path: Path) -> bool:
+    return path.is_file()