Add user management system with JWT authentication

- Database schema: users, permissions, client_access tables
- Auth: JWT tokens with Argon2 password hashing
- API: login, user CRUD, permission management
- Dashboard: login required, admin Users tab
- Auto-creates initial admin user on first run

server/static/dashboard.html

@@ -348,6 +348,7 @@
         <button class="tab" data-tab="access">Access</button>
         <button class="tab" data-tab="build">Build</button>
         <button class="tab" data-tab="settings">Settings</button>
+        <button class="tab admin-only" data-tab="users" style="display: none;">Users</button>
     </nav>
 
     <main class="content">
@@ -510,6 +511,21 @@
                 </p>
             </div>
         </div>
+
+        <!-- Users Tab (Admin Only) -->
+        <div class="tab-panel" id="users-panel">
+            <div class="card">
+                <div class="card-header">
+                    <div>
+                        <h2 class="card-title">User Management</h2>
+                        <p class="card-description">Manage user accounts and permissions</p>
+                    </div>
+                </div>
+                <p style="color: hsl(var(--muted-foreground));">
+                    <a href="/users" style="color: hsl(var(--primary));">Open User Management</a>
+                </p>
+            </div>
+        </div>
     </main>
 
     <!-- Chat Modal -->
@@ -546,19 +562,59 @@
         });
 
         // Check auth
-        const token = localStorage.getItem("token");
-        const user = JSON.parse(localStorage.getItem("user") || "null");
+        const token = localStorage.getItem("guruconnect_token");
+        const user = JSON.parse(localStorage.getItem("guruconnect_user") || "null");
 
-        if (!token) {
-            document.getElementById("userInfo").textContent = "Demo Mode";
-        } else if (user) {
-            document.getElementById("userInfo").textContent = user.email || user.name || "Technician";
+        // Verify authentication
+        async function checkAuth() {
+            if (!token) {
+                window.location.href = "/login";
+                return;
+            }
+
+            try {
+                const response = await fetch("/api/auth/me", {
+                    headers: { "Authorization": `Bearer ${token}` }
+                });
+
+                if (!response.ok) {
+                    localStorage.removeItem("guruconnect_token");
+                    localStorage.removeItem("guruconnect_user");
+                    window.location.href = "/login";
+                    return;
+                }
+
+                const userData = await response.json();
+
+                // Update user display
+                document.getElementById("userInfo").textContent = userData.username + " (" + userData.role + ")";
+
+                // Show admin-only elements
+                if (userData.role === "admin") {
+                    document.querySelectorAll(".admin-only").forEach(el => {
+                        el.style.display = "";
+                    });
+                }
+            } catch (err) {
+                console.error("Auth check failed:", err);
+                // Don't redirect on network error, just show what we have
+                if (user) {
+                    document.getElementById("userInfo").textContent = user.username || "User";
+                    if (user.role === "admin") {
+                        document.querySelectorAll(".admin-only").forEach(el => {
+                            el.style.display = "";
+                        });
+                    }
+                }
+            }
         }
 
+        checkAuth();
+
         // Logout
         document.getElementById("logoutBtn").addEventListener("click", () => {
-            localStorage.removeItem("token");
-            localStorage.removeItem("user");
+            localStorage.removeItem("guruconnect_token");
+            localStorage.removeItem("guruconnect_user");
             window.location.href = "/login";
         });