feat: GPU offload, signup limit, load tests & capacity planning

- Route all AI workloads (Ollama, STT, TTS, Image Gen) to GPU server
  (192.168.178.11) via LAN instead of host.docker.internal
- Upgrade default model to gemma3:12b and max concurrent to 5
- Add daily signup limit service (MAX_DAILY_SIGNUPS env var)
- Add GET /api/v1/auth/signup-status public endpoint
- Add k6 load test suite (web-apps, auth, sync-websocket, ollama)
- Add capacity planning documentation
- Fix: add eslint-config to sveltekit-base and calendar Dockerfiles

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

load-tests/web-apps.js

@@ -0,0 +1,72 @@
+/* eslint-disable no-undef */
+import http from 'k6/http';
+import { check, sleep } from 'k6';
+import { Rate, Trend } from 'k6/metrics';
+
+const errorRate = new Rate('errors');
+const appLatency = new Trend('app_latency', true);
+
+const BASE = __ENV.BASE_URL || 'http://localhost';
+
+// All deployed SvelteKit web apps with their ports
+const apps = [
+	{ name: 'dashboard', url: `${BASE}:5173` },
+	{ name: 'chat', url: `${BASE}:3000` },
+	{ name: 'todo', url: `${BASE}:5188` },
+	{ name: 'zitare', url: `${BASE}:5185` },
+	{ name: 'calendar', url: `${BASE}:5186` },
+	{ name: 'clock', url: `${BASE}:5187` },
+	{ name: 'contacts', url: `${BASE}:5176` },
+	{ name: 'storage', url: `${BASE}:5178` },
+	{ name: 'presi', url: `${BASE}:5180` },
+	{ name: 'manadeck', url: `${BASE}:5181` },
+	{ name: 'nutriphi', url: `${BASE}:5182` },
+	{ name: 'skilltree', url: `${BASE}:5183` },
+	{ name: 'photos', url: `${BASE}:5184` },
+	{ name: 'mukke', url: `${BASE}:5189` },
+	{ name: 'citycorners', url: `${BASE}:5190` },
+	{ name: 'picture', url: `${BASE}:5174` },
+	{ name: 'inventar', url: `${BASE}:5191` },
+];
+
+// When testing against production, use subdomains
+const prodApps = [
+	{ name: 'dashboard', url: 'https://mana.how' },
+	{ name: 'chat', url: 'https://chat.mana.how' },
+	{ name: 'todo', url: 'https://todo.mana.how' },
+	{ name: 'calendar', url: 'https://calendar.mana.how' },
+	{ name: 'clock', url: 'https://clock.mana.how' },
+];
+
+export const options = {
+	stages: [
+		{ duration: '30s', target: 10 }, // Ramp up
+		{ duration: '3m', target: 50 }, // Hold at 50 VUs
+		{ duration: '30s', target: 0 }, // Ramp down
+	],
+	thresholds: {
+		http_req_duration: ['p(95)<2000'], // 95% under 2s
+		errors: ['rate<0.05'], // <5% errors
+	},
+};
+
+export default function () {
+	const targets = __ENV.BASE_URL?.startsWith('https') ? prodApps : apps;
+	const app = targets[Math.floor(Math.random() * targets.length)];
+
+	const res = http.get(app.url, {
+		tags: { app: app.name },
+		timeout: '10s',
+	});
+
+	const success = check(res, {
+		'status is 200': (r) => r.status === 200,
+		'response has body': (r) => r.body && r.body.length > 0,
+		'response time < 2s': (r) => r.timings.duration < 2000,
+	});
+
+	errorRate.add(!success);
+	appLatency.add(res.timings.duration, { app: app.name });
+
+	sleep(Math.random() * 2 + 0.5); // 0.5-2.5s between requests
+}