feat(channels): add messaging channels and built-in qq bot

src/style/pages.css

@@ -2248,3 +2248,155 @@ details.docker-other-section[open] > .docker-other-toggle::before {
   white-space: pre-wrap;
   word-break: break-all;
 }
+
+/* ── 消息渠道管理 ── */
+
+.platforms-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
+  gap: var(--space-md);
+}
+
+.platform-card {
+  background: var(--bg-card);
+  border: 1px solid var(--border-primary);
+  border-radius: var(--radius-lg);
+  padding: var(--space-lg);
+  transition: all var(--transition-fast);
+}
+.platform-card:hover {
+  border-color: var(--border-focus);
+}
+.platform-card.active {
+  border-left: 3px solid var(--success, #22c55e);
+}
+.platform-card.inactive {
+  border-left: 3px solid var(--text-tertiary);
+  opacity: 0.75;
+}
+
+.platform-card-header {
+  display: flex;
+  align-items: center;
+  gap: var(--space-sm);
+  margin-bottom: var(--space-md);
+}
+.platform-emoji {
+  font-size: 22px;
+  line-height: 1;
+}
+.platform-name {
+  font-weight: 600;
+  font-size: var(--font-size-md);
+  flex: 1;
+}
+.platform-status-dot {
+  width: 8px;
+  height: 8px;
+  border-radius: 50%;
+  flex-shrink: 0;
+}
+.platform-status-dot.on {
+  background: var(--success, #22c55e);
+  box-shadow: 0 0 6px rgba(34, 197, 94, 0.4);
+}
+.platform-status-dot.off {
+  background: var(--text-tertiary);
+}
+
+.platform-card-actions {
+  display: flex;
+  gap: var(--space-xs);
+  flex-wrap: wrap;
+}
+
+/* 可接入平台选择按钮 */
+.platform-pick {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: var(--space-sm);
+  padding: var(--space-lg) var(--space-md);
+  background: var(--bg-card);
+  border: 1px solid var(--border-primary);
+  border-radius: var(--radius-lg);
+  cursor: pointer;
+  transition: all var(--transition-fast);
+  text-align: center;
+  color: var(--text-primary);
+}
+.platform-pick:hover {
+  border-color: var(--accent);
+  background: var(--accent-muted);
+}
+.platform-pick.configured {
+  border-color: var(--success, #22c55e);
+  background: rgba(34, 197, 94, 0.04);
+}
+.platform-pick-name {
+  font-weight: 600;
+  font-size: var(--font-size-md);
+}
+.platform-pick-desc {
+  font-size: var(--font-size-xs);
+  color: var(--text-tertiary);
+  line-height: 1.4;
+}
+.platform-pick-badge {
+  font-size: var(--font-size-xs);
+  font-weight: 600;
+  color: var(--success, #22c55e);
+  background: rgba(34, 197, 94, 0.1);
+  padding: 2px 8px;
+  border-radius: 999px;
+}
+
+/* 表单开关 */
+.toggle-switch {
+  position: relative;
+  display: inline-block;
+  width: 40px;
+  height: 22px;
+}
+.toggle-switch input {
+  opacity: 0;
+  width: 0;
+  height: 0;
+}
+.toggle-slider {
+  position: absolute;
+  inset: 0;
+  background: var(--bg-tertiary);
+  border-radius: 22px;
+  cursor: pointer;
+  transition: background 0.2s;
+}
+.toggle-slider::before {
+  content: '';
+  position: absolute;
+  width: 16px;
+  height: 16px;
+  left: 3px;
+  bottom: 3px;
+  background: white;
+  border-radius: 50%;
+  transition: transform 0.2s;
+}
+.toggle-switch input:checked + .toggle-slider {
+  background: var(--accent);
+}
+.toggle-switch input:checked + .toggle-slider::before {
+  transform: translateX(18px);
+}
+
+/* 加载占位 */
+.loading-placeholder {
+  background: linear-gradient(90deg, var(--bg-secondary) 25%, var(--bg-tertiary) 50%, var(--bg-secondary) 75%);
+  background-size: 200% 100%;
+  animation: shimmer 1.5s infinite;
+  border-radius: var(--radius-lg);
+}
+@keyframes shimmer {
+  0% { background-position: 200% 0; }
+  100% { background-position: -200% 0; }
+}