fix(editor): refresh the icon preview on outside icon writes

A10: the editor's icon preview is painted by a closure nothing outside can
reach, so a favicon fetched from Settings (or an import overwrite) updated
the cards and left the open editor showing the old initials. soIconField
publishes its painter; saveEntryIcon — the choke point for every icon write
— routes through editorAbsorbChange like tag/folder already do.

Also whitelists .toast and #busyOverlay in the editor's click-outside: both
can sit under the cursor during a long operation, and clicking one counted
as clicking away.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

js/app.favicon.js

@@ -52,7 +52,11 @@ async function saveEntryIcon(entryId, dataUri) {
             try { const b = await r.json(); if (b && b.error) msg = b.error; }
             catch (_) {}
             toast('Icon NOT saved: ' + msg, 'error');
+            return;
         }
+        // Choke point for every icon write (favicon backfill, upload, remove,
+        // import overwrite) — refresh the editor if it's open on this entry.
+        editorAbsorbChange(entryId, { icon: dataUri || '' });
     } catch (e) {
         toast('Icon save failed: ' + (e && e.message || e), 'error');
     }