v1.2.7: Phase 0 — CSS foundation + icons + snackbar

style.css: +93 lines — sidebar, view, tabs, toolbar, field (label on top),
  skeleton, snackbar, combobox classes. Font scale 13/14/16.
icons.js (NEW): 10 inline-SVG Lucide icons (play, edit, trash, check, x,
  chevronDown, search, plus, rotateCw, cloud). stroke=currentColor.
snackbar.js (NEW): showSnackbar(msg, type). bottom-right, 4s/8s auto-hide,
  stacking max 4, accessibility role=status aria-live=polite.
index.html: include icons.js before utils.js

site/static/js/snackbar.js

@@ -0,0 +1,30 @@
+// snackbar.js — лёгкие уведомления (без зависимостей)
+// showSnackbar(msg, type='info') — type: info, success, error
+
+function showSnackbar(msg, type) {
+    type = type || 'info';
+    let container = document.getElementById('snackbar-container');
+    if (!container) {
+        container = document.createElement('div');
+        container.id = 'snackbar-container';
+        container.className = 'snackbar-container';
+        container.setAttribute('role', 'status');
+        container.setAttribute('aria-live', 'polite');
+        document.body.appendChild(container);
+    }
+    const el = document.createElement('div');
+    el.className = 'snackbar ' + type;
+    el.textContent = msg;
+    el.onclick = function() { el.remove(); };
+    container.appendChild(el);
+
+    // Limit stacking
+    const all = container.querySelectorAll('.snackbar');
+    if (all.length > 4) all[0].remove();
+
+    // Auto-hide: info/success 4s, error 8s
+    const delay = (type === 'error') ? 8000 : 4000;
+    setTimeout(function() {
+        if (el.parentNode) el.remove();
+    }, delay);
+}