Add instance nav prefs, env config UI, and PM2 restart.

P1-P4: configurable nav/section visibility in system settings, full .env editor with restart badges, password change, runtime hot overrides, and single-instance pm2 restart. Works in hub embed iframe.
Co-authored-by: Cursor <cursoragent@cursor.com>

lib/instance/templates/display_prefs_panel.html

@@ -0,0 +1,12 @@
+{# 系统设置 · 导航显示开关 #}
+<div class="card settings-card settings-card--compact" id="display-prefs-card">
+    <h2>导航显示</h2>
+    <p class="settings-env-hint">以下开关控制顶栏导航与系统设置内区块是否显示，保存后立即生效。关键位监控、实盘下单、系统设置为固定项。</p>
+    <div id="display-prefs-form" class="display-prefs-form">
+        <div class="display-prefs-loading muted">加载中…</div>
+    </div>
+    <div class="settings-actions-row">
+        <button type="button" class="btn-primary btn-sm" id="display-prefs-save">保存导航设置</button>
+        <span class="settings-status-line" id="display-prefs-status"></span>
+    </div>
+</div>