Initial commit

Photo-based book cataloger with AI identification.
Room → Cabinet → Shelf → Book hierarchy; FastAPI + SQLite backend;
vanilla JS SPA; OpenAI-compatible plugin system for boundary
detection, text recognition, and archive search.

static/js/helpers.js

@@ -0,0 +1,21 @@
+/*
+ * helpers.js
+ * Pure utility functions with no dependencies on other application modules.
+ * Safe to call from any JS file.
+ *
+ * Provides: esc(), toast(), isDesktop()
+ */
+
+// ── Helpers ─────────────────────────────────────────────────────────────────
+function esc(s) {
+  return String(s ?? '').replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/"/g,'&quot;');
+}
+
+function toast(msg, dur = 2800) {
+  const el = document.getElementById('toast');
+  el.textContent = msg; el.classList.add('on');
+  clearTimeout(toast._t);
+  toast._t = setTimeout(() => el.classList.remove('on'), dur);
+}
+
+function isDesktop() { return window.innerWidth >= 768; }