feat: implement admin and OIDC authentication methods; add login and user info endpoints

Signed-off-by: Noste <83548733+Noooste@users.noreply.github.com>

frontend/src/types/auth.ts

@@ -0,0 +1,22 @@
+export interface AuthConfig {
+  admin: {
+    enabled: boolean;
+  };
+  oidc: {
+    enabled: boolean;
+    provider?: string;
+  };
+}
+
+export interface AuthUser {
+  username: string;
+  email?: string;
+  name?: string;
+}
+
+export interface AuthState {
+  user: AuthUser | null;
+  isAuthenticated: boolean;
+  isLoading: boolean;
+  error: string | null;
+}