feat(settings): add explicit settings dir override for sandboxed runs

Add LORA_MANAGER_SETTINGS_DIR env var and standalone --settings-path to pin
the settings location (settings.json, cache/, wildcards/, backups/, logs/,
stats/) to an arbitrary directory. The override takes precedence over
portable mode and the platform user config dir, and skips legacy migration,
so sandboxed dev/E2E runs no longer need to write settings.json in the repo
root or collide with the real instance.

standalone.py pre-scans argv for --settings-path at import time because the
settings location is resolved before main() parses arguments. SettingsManager
portable-switch migration is a no-op while the directory is pinned.

Update the lora-manager-e2e skill (prefer --settings-path sandboxing;
start_server.py passes it through) and the lora-manager-runtime-context
skill (document precedence; inspect script honors the override).

py/services/settings_manager.py

@@ -34,6 +34,8 @@ from ..utils.settings_paths import (
     APP_NAME,
     ensure_settings_file,
     get_legacy_settings_path,
+    get_settings_dir_override,
+    is_settings_dir_pinned,
 )
 from ..utils.tag_priorities import (
     PriorityTagEntry,
@@ -156,7 +158,10 @@ class SettingsManager:
         self._check_environment_variables()
         self._collect_configuration_warnings()
 
-        if os.environ.get("LORA_MANAGER_PORTABLE", "0") == "1":
+        if (
+            os.environ.get("LORA_MANAGER_PORTABLE", "0") == "1"
+            and not is_settings_dir_pinned()
+        ):
             if not self.settings.get("use_portable_settings"):
                 self.settings["use_portable_settings"] = True
                 self._save_settings()
@@ -1641,6 +1646,15 @@ class SettingsManager:
     def _prepare_portable_switch(self, use_portable: bool) -> None:
         """Prepare switching the settings storage location."""
 
+        if is_settings_dir_pinned():
+            logger.info(
+                "Portable-mode switch ignored: settings directory is pinned via "
+                "%s/--settings-path (%s)",
+                "LORA_MANAGER_SETTINGS_DIR",
+                get_settings_dir_override(),
+            )
+            return
+
         legacy_path = get_legacy_settings_path()
         user_dir = self._get_user_config_directory()
         user_settings_path = os.path.join(user_dir, "settings.json")