perf: switch to SSE dispatched changes

Previously we would use naive revalidators which would invalidate EVERY
SINGLE action loader every 3 seconds, resulting in several fetches. It
would also bubble fetches across the layout actions into the individual
pages.

This new approach selectively has live stores of resources which then
poll for changes on the server side and then dispatches updates to the
client via a new /events/live SSE endpoint.

app/routes/users/overview.tsx

@@ -1,6 +1,7 @@
 import { createHash } from "node:crypto";
 
 import PageError from "~/components/page-error";
+import { nodesResource, usersResource } from "~/server/headscale/live-store";
 import { Capabilities, Roles } from "~/server/web/roles";
 import type { Role } from "~/server/web/roles";
 import type { Machine, User } from "~/types";
@@ -55,7 +56,12 @@ export async function loader({ request, context }: Route.LoaderArgs) {
   try {
     const apiKey = context.auth.getHeadscaleApiKey(principal, context.oidc?.apiKey);
     const api = context.hsApi.getRuntimeClient(apiKey);
-    [nodes, apiUsers] = await Promise.all([api.getNodes(), api.getUsers()]);
+    const [nodesSnap, usersSnap] = await Promise.all([
+      context.hsLive.get(nodesResource, api),
+      context.hsLive.get(usersResource, api),
+    ]);
+    nodes = nodesSnap.data;
+    apiUsers = usersSnap.data;
   } catch (error) {
     log.warn("api", "Failed to fetch Headscale API data: %s", String(error));
     apiError =

app/routes/users/user-actions.ts

@@ -1,5 +1,6 @@
 import { data } from "react-router";
 
+import { usersResource } from "~/server/headscale/live-store";
 import { getOidcSubject } from "~/server/web/headscale-identity";
 import { Capabilities } from "~/server/web/roles";
 import type { Role } from "~/server/web/roles";
@@ -38,6 +39,7 @@ export async function userAction({ request, context }: Route.ActionArgs) {
       }
 
       await api.createUser(name, email, displayName);
+      await context.hsLive.refresh(usersResource, api);
       return { message: "User created successfully" };
     }
     case "delete_user": {
@@ -49,6 +51,7 @@ export async function userAction({ request, context }: Route.ActionArgs) {
       }
 
       await api.deleteUser(userId);
+      await context.hsLive.refresh(usersResource, api);
       return { message: "User deleted successfully" };
     }
     case "rename_user": {
@@ -72,6 +75,7 @@ export async function userAction({ request, context }: Route.ActionArgs) {
       }
 
       await api.renameUser(userId, newName);
+      await context.hsLive.refresh(usersResource, api);
       return { message: "User renamed successfully" };
     }
     case "reassign_user": {