feat: Add multi-step Setup Wizard for Pulse 5.0 onboarding

- New SetupWizard component with 5-step flow:
  1. Welcome: Bootstrap token unlock, platform showcase
  2. Security: Admin account + API token creation
  3. Connect: Multi-platform infrastructure (Proxmox, Docker, K8s)
  4. Features: AI and auto-updates toggles
  5. Complete: Credentials display with copy/download

- Replaced FirstRunSetup with SetupWizard in Login.tsx
- Added Install Update button to UpdatesSettingsPanel
- Enhanced UpdatesSettingsPanel with update plan integration
- Added UpdateConfirmationModal to Settings for inline updates

Positions Pulse as a unified infrastructure monitoring platform,
not just a Proxmox-specific tool.

frontend-modern/src/components/SetupWizard/steps/WelcomeStep.tsx

@@ -0,0 +1,156 @@
+import { Component, createSignal, Show } from 'solid-js';
+import { showError, showSuccess } from '@/utils/toast';
+
+interface WelcomeStepProps {
+    onNext: () => void;
+    bootstrapToken: string;
+    setBootstrapToken: (token: string) => void;
+    isUnlocked: boolean;
+    setIsUnlocked: (unlocked: boolean) => void;
+}
+
+export const WelcomeStep: Component<WelcomeStepProps> = (props) => {
+    const [isValidating, setIsValidating] = createSignal(false);
+    const [tokenPath, setTokenPath] = createSignal('');
+    const [isDocker, setIsDocker] = createSignal(false);
+    const [inContainer, setInContainer] = createSignal(false);
+    const [lxcCtid, setLxcCtid] = createSignal('');
+
+    // Fetch bootstrap info on mount
+    const fetchBootstrapInfo = async () => {
+        try {
+            const response = await fetch('/api/security/status');
+            if (response.ok) {
+                const data = await response.json();
+                if (data.bootstrapTokenPath) {
+                    setTokenPath(data.bootstrapTokenPath);
+                    setIsDocker(data.isDocker || false);
+                    setInContainer(data.inContainer || false);
+                    setLxcCtid(data.lxcCtid || '');
+                }
+            }
+        } catch (error) {
+            console.error('Failed to fetch bootstrap info:', error);
+        }
+    };
+
+    // Call on component load
+    fetchBootstrapInfo();
+
+    const handleUnlock = async () => {
+        if (!props.bootstrapToken.trim()) {
+            showError('Please enter the bootstrap token');
+            return;
+        }
+
+        setIsValidating(true);
+        try {
+            const response = await fetch('/api/security/validate-bootstrap-token', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ token: props.bootstrapToken.trim() }),
+            });
+
+            if (!response.ok) {
+                throw new Error('Invalid bootstrap token');
+            }
+
+            props.setIsUnlocked(true);
+            showSuccess('Token verified!');
+            props.onNext();
+        } catch (error) {
+            showError('Invalid bootstrap token. Please check and try again.');
+        } finally {
+            setIsValidating(false);
+        }
+    };
+
+    const getTokenCommand = () => {
+        const path = tokenPath() || '/etc/pulse/.bootstrap_token';
+        if (isDocker()) {
+            return `docker exec <container> cat ${path}`;
+        }
+        if (inContainer() && lxcCtid()) {
+            return `pct exec ${lxcCtid()} -- cat ${path}`;
+        }
+        if (inContainer()) {
+            return `pct exec <ctid> -- cat ${path}`;
+        }
+        return `cat ${path}`;
+    };
+
+    return (
+        <div class="text-center">
+            {/* Logo */}
+            <div class="mb-8">
+                <div class="inline-flex items-center justify-center w-24 h-24 rounded-full bg-gradient-to-br from-blue-500 to-indigo-600 shadow-2xl shadow-blue-500/30 mb-6">
+                    <svg width="56" height="56" viewBox="0 0 256 256" class="text-white">
+                        <circle class="fill-current opacity-20" cx="128" cy="128" r="122" />
+                        <circle class="fill-none stroke-current" stroke-width="14" cx="128" cy="128" r="84" opacity="0.9" />
+                        <circle class="fill-current" cx="128" cy="128" r="26" />
+                    </svg>
+                </div>
+                <h1 class="text-4xl font-bold text-white mb-3">
+                    Welcome to Pulse
+                </h1>
+                <p class="text-xl text-blue-200/80">
+                    Unified infrastructure monitoring
+                </p>
+            </div>
+
+            {/* Feature highlights */}
+            <div class="grid grid-cols-3 gap-4 mb-8">
+                <div class="bg-white/5 backdrop-blur rounded-xl p-4 border border-white/10">
+                    <div class="text-2xl mb-2">🖥️</div>
+                    <div class="text-sm text-white/80">Proxmox</div>
+                </div>
+                <div class="bg-white/5 backdrop-blur rounded-xl p-4 border border-white/10">
+                    <div class="text-2xl mb-2">🐳</div>
+                    <div class="text-sm text-white/80">Docker</div>
+                </div>
+                <div class="bg-white/5 backdrop-blur rounded-xl p-4 border border-white/10">
+                    <div class="text-2xl mb-2">☸️</div>
+                    <div class="text-sm text-white/80">Kubernetes</div>
+                </div>
+            </div>
+
+            {/* Bootstrap token unlock */}
+            <Show when={!props.isUnlocked}>
+                <div class="bg-white/10 backdrop-blur-xl rounded-2xl p-6 border border-white/20 text-left">
+                    <h3 class="text-lg font-semibold text-white mb-2">Unlock Setup</h3>
+                    <p class="text-sm text-white/70 mb-4">
+                        Retrieve the bootstrap token from your host:
+                    </p>
+                    <div class="bg-black/30 rounded-lg p-3 font-mono text-sm text-green-400 mb-4">
+                        {getTokenCommand()}
+                    </div>
+                    <input
+                        type="text"
+                        value={props.bootstrapToken}
+                        onInput={(e) => props.setBootstrapToken(e.currentTarget.value)}
+                        onKeyPress={(e) => e.key === 'Enter' && handleUnlock()}
+                        class="w-full px-4 py-3 bg-white/10 border border-white/20 rounded-xl text-white placeholder-white/40 focus:outline-none focus:ring-2 focus:ring-blue-500 font-mono"
+                        placeholder="Paste your bootstrap token"
+                        autofocus
+                    />
+                    <button
+                        onClick={handleUnlock}
+                        disabled={isValidating() || !props.bootstrapToken.trim()}
+                        class="w-full mt-4 py-3 px-6 bg-gradient-to-r from-blue-500 to-indigo-600 hover:from-blue-600 hover:to-indigo-700 disabled:opacity-50 disabled:cursor-not-allowed text-white font-medium rounded-xl transition-all shadow-lg shadow-blue-500/25"
+                    >
+                        {isValidating() ? 'Validating...' : 'Continue →'}
+                    </button>
+                </div>
+            </Show>
+
+            <Show when={props.isUnlocked}>
+                <button
+                    onClick={props.onNext}
+                    class="py-4 px-8 bg-gradient-to-r from-blue-500 to-indigo-600 hover:from-blue-600 hover:to-indigo-700 text-white text-lg font-medium rounded-xl transition-all shadow-lg shadow-blue-500/25"
+                >
+                    Get Started →
+                </button>
+            </Show>
+        </div>
+    );
+};