Ship K-design admin with multi-channel support and polish.

Replace placeholder admin pages with the design system, add analytics/customers/categories/inventory/settings, channel pricing and order sources, plus skeleton loaders and clean motion.

Co-authored-by: Cursor <cursoragent@cursor.com>

design/admin/01-login.html

@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <title>Login — iLED Admin</title>
+    <link rel="stylesheet" href="assets/admin-k.css" />
+  </head>
+  <body>
+    <div class="login-page">
+      <div class="card login-card">
+        <div class="login-brand">
+          <span class="mark" style="width: 32px; height: 32px; border-radius: 8px; background: var(--accent); display: grid; place-items: center"><svg class="ico" aria-hidden="true"><use href="#i-bulb"></use></svg></span>
+          iLED Admin
+        </div>
+        <p class="login-sub">Sign in to manage catalog, orders, and marketing.</p>
+
+        <!-- Demo error: remove class hidden to show -->
+        <div class="form-error mb-16" id="login-error" hidden>
+          Invalid email or password. Admin role required.
+        </div>
+
+        <form class="stack" action="02-dashboard.html" method="get">
+          <div class="field">
+            <label for="email">Email</label>
+            <input class="input" id="email" name="email" type="email" placeholder="admin@iled.pl" value="admin@iled.pl" required />
+          </div>
+          <div class="field">
+            <label for="password">Password</label>
+            <input class="input" id="password" name="password" type="password" placeholder="••••••••" value="Admin123!" required />
+          </div>
+          <button class="btn btn-primary w-full" type="submit" style="height: 42px; margin-top: 4px">
+            Sign in
+          </button>
+          <button class="btn btn-ghost w-full" type="button" id="demo-error">
+            Demo: show error state
+          </button>
+        </form>
+        <p class="field-hint" style="margin-top: 20px; text-align: center">
+          <a href="index.html">← Mock gallery</a>
+        </p>
+      </div>
+    </div>
+    <script>
+      document.getElementById("demo-error").addEventListener("click", function () {
+        document.getElementById("login-error").hidden = false;
+      });
+    </script>
+      <script src="assets/admin-k.js"></script>
+  </body>
+</html>