feat(auth): support reverse-proxy driven proxy auth

Closes HP-353.

app/routes/users/overview.tsx

@@ -2,6 +2,7 @@ import { createHash } from "node:crypto";
 
 import PageError from "~/components/page-error";
 import { nodesResource, usersResource } from "~/server/headscale/live-store";
+import { isUserPrincipal } from "~/server/web/auth";
 import { Capabilities, Roles } from "~/server/web/roles";
 import type { Role } from "~/server/web/roles";
 import type { Machine, User } from "~/types";
@@ -131,11 +132,11 @@ export async function loader({ request, context }: Route.LoaderArgs) {
     }
   }
 
-  const isOwner = principal.kind === "oidc" && principal.user.role === "owner";
+  const isOwner = isUserPrincipal(principal) && principal.user.role === "owner";
 
   return {
     writable: writablePermission,
-    currentUserId: principal.kind === "oidc" ? principal.user.id : undefined,
+    currentUserId: isUserPrincipal(principal) ? principal.user.id : undefined,
     isOwner,
     oidc: context.config.oidc ? { issuer: context.config.oidc.issuer } : undefined,
     magic,

app/routes/users/user-actions.ts

@@ -1,6 +1,7 @@
 import { data } from "react-router";
 
 import { usersResource } from "~/server/headscale/live-store";
+import { isUserPrincipal } from "~/server/web/auth";
 import { Capabilities } from "~/server/web/roles";
 import type { Role } from "~/server/web/roles";
 
@@ -93,7 +94,7 @@ export async function userAction({ request, context }: Route.ActionArgs) {
       return { message: "User reassigned successfully" };
     }
     case "transfer_ownership": {
-      if (principal.kind !== "oidc" || principal.user.role !== "owner") {
+      if (!isUserPrincipal(principal) || principal.user.role !== "owner") {
         throw data("Only the owner can transfer ownership.", { status: 403 });
       }