Cleanup: fix eslint warnings, button loading state, inspector footer hint

- app.js: replace != with !== (eqeqeq rule) on resolved_24h null check
  and totalActive pagination check
- style.css: extend loading state to all .lt-btn.is-loading (not just
  refresh button), so suppressions form submit shows disabled feedback;
  remove dead .link-collapse-bar rule
- base.html: add inspector page to footer R=REFRESH hint; update
  keyboard shortcut table to include Inspector in refresh shortcut doc

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

static/style.css

@@ -83,13 +83,16 @@
   .lt-main.lt-container { padding-top: calc(46px + var(--space-sm)); }
 }
 
-/* ── Refresh button loading state ────────────────────────────────── */
-[data-action="refresh"].is-loading {
+/* ── Button loading state ─────────────────────────────────────────── */
+[data-action="refresh"].is-loading,
+.lt-btn.is-loading {
   opacity: .5;
   pointer-events: none;
   cursor: wait;
+  position: relative;
 }
-[data-action="refresh"].is-loading::after {
+[data-action="refresh"].is-loading::after,
+.lt-btn.is-loading::after {
   content: '…';
 }
 
@@ -587,7 +590,6 @@
 .panel-toggle   { font-size: .65em; color: var(--text-muted); flex-shrink: 0; margin-left: 6px; padding: 0 4px; border: 1px solid var(--border-color); }
 .link-host-panel.collapsed > .link-ifaces-grid { display: none; }
 
-.link-collapse-bar { display: flex; gap: 8px; margin-bottom: 10px; }
 
 .link-ifaces-grid {
   display: grid;