feat: add MCP servers dashboard page with CRUD and token management

New page at /mcp-servers to register, view, and manage MCP server
instances. Shows endpoint config, enabled tools, and access tokens
with reveal/regenerate controls. Includes McpServerConfig model in
compliance-core, MongoDB collection accessor, server functions for
list/add/delete/regenerate-token, sidebar nav entry, and full CSS.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

assets/main.css

@@ -533,3 +533,215 @@ tr:hover {
     color: var(--text-secondary);
     opacity: 0.6;
 }
+
+/* ── Utility classes ────────────────────────────────────── */
+
+.mb-3 { margin-bottom: 12px; }
+.mb-4 { margin-bottom: 16px; }
+.text-secondary { color: var(--text-secondary); }
+
+.btn-sm {
+    padding: 4px 10px;
+    font-size: 12px;
+}
+
+.btn-danger {
+    background: var(--danger);
+    color: #fff;
+}
+.btn-danger:hover {
+    background: #dc2626;
+}
+
+.btn-secondary {
+    background: var(--bg-secondary);
+    color: var(--text-primary);
+    border: 1px solid var(--border);
+}
+.btn-secondary:hover {
+    background: var(--bg-primary);
+}
+
+/* ── Modal ──────────────────────────────────────────────── */
+
+.modal-overlay {
+    position: fixed;
+    inset: 0;
+    background: rgba(0, 0, 0, 0.6);
+    backdrop-filter: blur(4px);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    z-index: 1000;
+}
+
+.modal-dialog {
+    background: var(--bg-secondary);
+    border: 1px solid var(--border);
+    border-radius: 12px;
+    padding: 24px;
+    max-width: 440px;
+    width: 90%;
+}
+
+.modal-dialog h3 {
+    margin-bottom: 12px;
+}
+
+.modal-dialog p {
+    margin-bottom: 8px;
+    font-size: 14px;
+    color: var(--text-secondary);
+}
+
+.modal-warning {
+    color: var(--warning) !important;
+    font-size: 13px !important;
+}
+
+.modal-actions {
+    display: flex;
+    gap: 8px;
+    justify-content: flex-end;
+    margin-top: 16px;
+}
+
+/* ── MCP Servers ────────────────────────────────────────── */
+
+.mcp-server-card {
+    padding: 20px;
+}
+
+.mcp-server-header {
+    display: flex;
+    justify-content: space-between;
+    align-items: flex-start;
+    margin-bottom: 12px;
+}
+
+.mcp-server-title {
+    display: flex;
+    align-items: center;
+    gap: 10px;
+}
+
+.mcp-server-title h3 {
+    font-size: 16px;
+    font-weight: 600;
+    margin: 0;
+}
+
+.mcp-server-actions {
+    display: flex;
+    gap: 6px;
+}
+
+.mcp-status {
+    display: inline-flex;
+    align-items: center;
+    padding: 2px 10px;
+    border-radius: 20px;
+    font-size: 11px;
+    font-weight: 600;
+    text-transform: uppercase;
+    letter-spacing: 0.5px;
+}
+
+.mcp-status-running {
+    background: rgba(34, 197, 94, 0.15);
+    color: var(--success);
+}
+
+.mcp-status-stopped {
+    background: rgba(148, 163, 184, 0.15);
+    color: var(--text-secondary);
+}
+
+.mcp-status-error {
+    background: rgba(239, 68, 68, 0.15);
+    color: var(--danger);
+}
+
+.mcp-config-grid {
+    display: grid;
+    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
+    gap: 12px;
+    margin-bottom: 16px;
+}
+
+.mcp-config-item {
+    display: flex;
+    flex-direction: column;
+    gap: 4px;
+}
+
+.mcp-config-label {
+    font-size: 11px;
+    font-weight: 600;
+    text-transform: uppercase;
+    letter-spacing: 0.5px;
+    color: var(--text-secondary);
+}
+
+.mcp-config-value {
+    font-size: 13px;
+    color: var(--text-primary);
+    word-break: break-all;
+}
+
+.mcp-form-grid {
+    display: grid;
+    grid-template-columns: 1fr 1fr;
+    gap: 0 16px;
+}
+
+.mcp-tools-section {
+    margin-bottom: 16px;
+}
+
+.mcp-tools-list {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 6px;
+    margin-top: 6px;
+}
+
+.mcp-tool-badge {
+    display: inline-block;
+    padding: 3px 10px;
+    background: rgba(56, 189, 248, 0.1);
+    border: 1px solid rgba(56, 189, 248, 0.2);
+    border-radius: 6px;
+    font-size: 12px;
+    font-family: 'JetBrains Mono', monospace;
+    color: var(--accent);
+}
+
+.mcp-token-section {
+    margin-bottom: 12px;
+}
+
+.mcp-token-row {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    margin-top: 6px;
+}
+
+.mcp-token-value {
+    flex: 1;
+    padding: 6px 10px;
+    background: var(--bg-primary);
+    border: 1px solid var(--border);
+    border-radius: 6px;
+    font-size: 12px;
+    font-family: 'JetBrains Mono', monospace;
+    color: var(--text-secondary);
+    word-break: break-all;
+}
+
+.mcp-meta {
+    padding-top: 12px;
+    border-top: 1px solid var(--border);
+    font-size: 12px;
+}