feat: preffered startup paths

webui/backend/app/services/settings_service.py

@@ -2,22 +2,54 @@ from __future__ import annotations
 
 from backend.app.api.schemas import SettingsResponse, SettingsUpdateRequest
 from backend.app.db.settings_repository import SettingsRepository
+from backend.app.security.path_guard import PathGuard
 
 
 class SettingsService:
-    def __init__(self, repository: SettingsRepository):
+    def __init__(self, repository: SettingsRepository, path_guard: PathGuard):
         self._repository = repository
+        self._path_guard = path_guard
 
     def get_settings(self) -> SettingsResponse:
         values = self._repository.get_settings()
-        return SettingsResponse(show_thumbnails=self._as_bool(values.get("show_thumbnails"), default=False))
+        preferred_left = self._as_optional_str(values.get("preferred_startup_path_left"))
+        preferred_right = self._as_optional_str(values.get("preferred_startup_path_right"))
+        legacy_preferred = self._as_optional_str(values.get("preferred_startup_path"))
+        return SettingsResponse(
+            show_thumbnails=self._as_bool(values.get("show_thumbnails"), default=False),
+            preferred_startup_path_left=preferred_left or legacy_preferred,
+            preferred_startup_path_right=preferred_right,
+        )
 
     def update_settings(self, request: SettingsUpdateRequest) -> SettingsResponse:
-        self._repository.set_setting("show_thumbnails", "true" if request.show_thumbnails else "false")
+        if request.show_thumbnails is not None:
+            self._repository.set_setting("show_thumbnails", "true" if request.show_thumbnails else "false")
+
+        if request.preferred_startup_path_left is not None:
+            self._set_directory_setting("preferred_startup_path_left", request.preferred_startup_path_left)
+
+        if request.preferred_startup_path_right is not None:
+            self._set_directory_setting("preferred_startup_path_right", request.preferred_startup_path_right)
+
         return self.get_settings()
 
+    def _set_directory_setting(self, key: str, value: str) -> None:
+        normalized = value.strip()
+        if not normalized:
+            self._repository.set_setting(key, "")
+            return
+        resolved = self._path_guard.resolve_directory_path(normalized)
+        self._repository.set_setting(key, resolved.relative)
+
     @staticmethod
     def _as_bool(value: str | None, default: bool) -> bool:
         if value is None:
             return default
         return value.strip().lower() in {"1", "true", "yes", "on"}
+
+    @staticmethod
+    def _as_optional_str(value: str | None) -> str | None:
+        if value is None:
+            return None
+        normalized = value.strip()
+        return normalized or None