feat: OIDC configuration in global Settings (ENV or DB)

- Add oidc_* attributes to Setting, migration and Config helpers
- Secrets and OidcRoleSyncConfig read from Config (ENV overrides DB)
- GlobalSettingsLive: OIDC section with disabled fields when ENV set
- OIDC role sync tests use DataCase for DB access

lib/mv/oidc_role_sync_config.ex

@@ -2,23 +2,19 @@ defmodule Mv.OidcRoleSyncConfig do
   @moduledoc """
   Runtime configuration for OIDC group → role sync (e.g. admin group → Admin role).
 
-  Reads from Application config `:mv, :oidc_role_sync`:
-  - `:admin_group_name` – OIDC group name that maps to Admin role (optional; when nil, no sync).
-  - `:groups_claim` – JWT/user_info claim name for groups (default: `"groups"`).
+  Reads from Mv.Config (ENV first, then Settings):
+  - `oidc_admin_group_name/0` – OIDC group name that maps to Admin role (optional; when nil, no sync).
+  - `oidc_groups_claim/0` – JWT/user_info claim name for groups (default: `"groups"`).
 
-  Set via ENV in production: OIDC_ADMIN_GROUP_NAME, OIDC_GROUPS_CLAIM (see config/runtime.exs).
+  Set via ENV: OIDC_ADMIN_GROUP_NAME, OIDC_GROUPS_CLAIM; or via Settings (Basic settings → OIDC).
   """
   @doc "Returns the OIDC group name that maps to Admin role, or nil if not configured."
   def oidc_admin_group_name do
-    get(:admin_group_name)
+    Mv.Config.oidc_admin_group_name()
   end
 
   @doc "Returns the JWT/user_info claim name for groups; defaults to \"groups\"."
   def oidc_groups_claim do
-    get(:groups_claim) || "groups"
-  end
-
-  defp get(key) do
-    Application.get_env(:mv, :oidc_role_sync, []) |> Keyword.get(key)
+    Mv.Config.oidc_groups_claim() || "groups"
   end
 end