Add Factorio World Management feature to GSM

- Add gsm-frontend to repository (React + Vite + TailwindCSS)
- New "Worlds" tab for Factorio server with:
  - List saved worlds with Start/Delete actions
  - Create new world with full map generation parameters
  - Preset selection (Default, Rich Resources, Rail World, etc.)
  - Save custom configurations as templates
- Show which save will be loaded in Overview tab
- Lock world management while server is running
- Backend changes deployed to server separately

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

gsm-frontend/src/pages/Dashboard.jsx

@@ -0,0 +1,168 @@
+import { useState, useEffect } from 'react'
+import { useNavigate } from 'react-router-dom'
+import { getServers } from '../api'
+import { useUser } from '../context/UserContext'
+import ServerCard from '../components/ServerCard'
+import SettingsModal from '../components/SettingsModal'
+import UserManagement from '../components/UserManagement'
+import LoginModal from '../components/LoginModal'
+
+export default function Dashboard({ onLogin, onLogout }) {
+  const navigate = useNavigate()
+  const { user, token, loading: userLoading, isSuperadmin, role } = useUser()
+  const [servers, setServers] = useState([])
+  const [loading, setLoading] = useState(true)
+  const [error, setError] = useState('')
+  const [showSettings, setShowSettings] = useState(false)
+  const [showUserMgmt, setShowUserMgmt] = useState(false)
+  const [showLogin, setShowLogin] = useState(false)
+
+  const isAuthenticated = !!token
+
+  const fetchServers = async () => {
+    try {
+      const data = await getServers(token)
+      setServers(data)
+      setError('')
+    } catch (err) {
+      if (err.message.includes('401') || err.message.includes('403')) {
+        if (isAuthenticated) {
+          onLogout()
+        }
+      } else {
+        setError('Failed to connect to server')
+      }
+    } finally {
+      setLoading(false)
+    }
+  }
+
+  useEffect(() => {
+    if (!userLoading) {
+      fetchServers()
+      const interval = setInterval(fetchServers, 10000)
+      return () => clearInterval(interval)
+    }
+  }, [token, userLoading])
+
+  const roleLabels = {
+    user: 'Viewer',
+    moderator: 'Operator',
+    superadmin: 'Admin'
+  }
+
+  if (userLoading) {
+    return (
+      <div className="min-h-screen flex items-center justify-center">
+        <div className="text-neutral-400">Loading...</div>
+      </div>
+    )
+  }
+
+  const onlineCount = servers.filter(s => s.running).length
+  document.title = 'Dashboard | Zeasy GSM'
+  const totalPlayers = servers.reduce((sum, s) => sum + (s.players?.online || 0), 0)
+
+  return (
+    <div className="min-h-screen page-enter">
+      {/* Header */}
+      <header className="border-b border-neutral-800 bg-neutral-900/50 backdrop-blur-sm sticky top-0 z-10">
+        <div className="container-main py-4">
+          <div className="flex items-center justify-between">
+            <div className="flex items-center gap-3">
+              <a href="https://zeasy.software" target="_blank" rel="noopener noreferrer" className="relative block group"><img src="/navbarlogograuer.png" alt="Logo" className="h-8 transition-opacity duration-300 group-hover:opacity-0" /><img src="/navbarlogoweiß.png" alt="Logo" className="h-8 absolute top-0 left-0 opacity-0 transition-opacity duration-300 group-hover:opacity-100" /></a>
+              <span className="text-xl font-semibold text-white hidden sm:inline">Gameserver Management</span>
+            </div>
+            <div className="hidden md:flex items-center gap-4 text-sm text-neutral-400">
+              <span>
+                <span className="text-white font-medium">{onlineCount}</span>/{servers.length} online
+              </span>
+              <span className="text-neutral-600">|</span>
+              <span>
+                <span className="text-white font-medium">{totalPlayers}</span> players
+              </span>
+            </div>
+            <div className="flex items-center gap-3">
+              {isAuthenticated ? (
+                <>
+                  <div className="hidden sm:block text-right mr-2">
+                    <div className="text-sm text-white">{user?.username}</div>
+                    <div className="text-xs text-neutral-500">{roleLabels[role]}</div>
+                  </div>
+                  {isSuperadmin && (
+                    <button
+                      onClick={() => setShowUserMgmt(true)}
+                      className="btn btn-ghost"
+                    >
+                      Users
+                    </button>
+                  )}
+                  <button
+                    onClick={() => setShowSettings(true)}
+                    className="btn btn-ghost"
+                  >
+                    Settings
+                  </button>
+                  <button
+                    onClick={onLogout}
+                    className="btn btn-outline"
+                  >
+                    Sign out
+                  </button>
+                </>
+              ) : (
+                <button
+                  onClick={() => setShowLogin(true)}
+                  className="btn btn-primary"
+                >
+                  Sign in
+                </button>
+              )}
+            </div>
+          </div>
+        </div>
+      </header>
+
+      {/* Main Content */}
+      <main className="container-main py-8">
+        {error && (
+          <div className="mb-6 alert alert-error fade-in">
+            {error}
+          </div>
+        )}
+        {loading ? (
+          <div className="text-center py-12">
+            <div className="text-neutral-400">Loading servers...</div>
+          </div>
+        ) : (
+          <div className="grid grid-cols-1 md:grid-cols-2 gap-6">
+            {servers.map((server, index) => (
+              <div
+                key={server.id}
+                className="fade-in-up"
+                style={{ animationDelay: index * 50 + 'ms', animationFillMode: 'both' }}
+              >
+                <ServerCard
+                  server={server}
+                  onClick={() => navigate('/server/' + server.id)}
+                  isAuthenticated={isAuthenticated}
+                />
+              </div>
+            ))}
+          </div>
+        )}
+      </main>
+
+      {/* Modals */}
+      {showSettings && (
+        <SettingsModal onClose={() => setShowSettings(false)} />
+      )}
+      {showUserMgmt && (
+        <UserManagement onClose={() => setShowUserMgmt(false)} />
+      )}
+      {showLogin && (
+        <LoginModal onLogin={onLogin} onClose={() => setShowLogin(false)} />
+      )}
+    </div>
+  )
+}