fix(badges): auto-save font sizes on adjustment

Font size changes now persist automatically (600ms debounce) without
requiring the user to find and click Lock Sizes in the collapsed Staff
section. reset_font_sizes_to_auto continues to handle its own save.

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

src/routes/events/[event_id]/(badges)/badges/[badge_id]/ae_comp__badge_print_controls.svelte

@@ -731,6 +731,34 @@ async function reset_font_sizes_to_auto() {
     }
 }
 
+// --- Auto-save font sizes on change ---
+// When a trusted user adjusts font sizes the change is saved automatically after a
+// short debounce so they don't have to find and click "Lock Sizes" every time.
+// WHY: the Lock Sizes button is in the Staff section (starts collapsed) and users
+// routinely adjusted font sizes and then reloaded, losing their changes.
+// reset_font_sizes_to_auto handles its own save, so we only auto-save when at
+// least one size is non-null (i.e. the "reset to auto" path is excluded here).
+let _font_auto_save_timer: ReturnType<typeof setTimeout> | null = null;
+$effect(() => {
+    // Re-read the dirty+override signals inside the effect so Svelte tracks them.
+    const dirty = sizes_are_dirty;
+    const has_override = has_any_size_override;
+    if (!dirty || !has_override || !is_trusted || !$lq__event_badge_obj?.event_badge_id) {
+        return;
+    }
+    if (_font_auto_save_timer !== null) clearTimeout(_font_auto_save_timer);
+    _font_auto_save_timer = setTimeout(() => {
+        _font_auto_save_timer = null;
+        lock_font_sizes();
+    }, 600);
+    return () => {
+        if (_font_auto_save_timer !== null) {
+            clearTimeout(_font_auto_save_timer);
+            _font_auto_save_timer = null;
+        }
+    };
+});
+
 // TC modal ref for the lead scanning terms & conditions dialog
 let tc_dialog_ref: HTMLDialogElement | undefined;