fix(emoji-picker): surface silent upload failures + fix stale grid refresh

lib/public/modules/emoji-picker.js

@@ -249,12 +249,24 @@ export function buildEmojiPicker(opts) {
     }
 
     function doUpload() {
-      if (!pendingFile) return;
+      // Both early returns below used to be silent — the control (rendered
+      // by showSlugConfirm) is only reachable once a file is already
+      // selected, but a defensive check that fires with zero user feedback
+      // is indistinguishable from the picker doing nothing at all. Surface
+      // both via the same toast used for server-side upload failures (line
+      // ~285) so "nothing happened" never happens silently again.
+      if (!pendingFile) {
+        showToast("Couldn't add custom emoji", "warn");
+        return;
+      }
       var slug = slugInput.value.trim().toLowerCase()
         .replace(/[^a-z0-9_-]+/g, "-")
         .replace(/^-+|-+$/g, "")
         .slice(0, 64);
-      if (!slug || !/^[a-z0-9_-]{1,64}$/.test(slug)) return;
+      if (!slug || !/^[a-z0-9_-]{1,64}$/.test(slug)) {
+        showToast("Enter a valid name", "warn");
+        return;
+      }
 
       // Check for duplicate in the already-fetched list
       var existing = customList || [];
@@ -274,9 +286,14 @@ export function buildEmojiPicker(opts) {
             showToast(result.error || "Upload failed", "warn");
             return;
           }
-          // Refresh the custom grid after upload
+          // Refresh the custom grid after upload. buildCustomPanel() already
+          // repaints the grid it just (re)built via its own fresh
+          // renderCustomGrid closure (see below) — calling the outer
+          // renderCustomGrid here re-renders the ORPHANED grid captured by
+          // this closure at the time doUpload's panel was built, which is
+          // detached from the DOM the moment buildCustomPanel() runs again.
           customList = null;
-          fetchCustomList(function () { buildCustomPanel(); renderCustomGrid(); });
+          fetchCustomList(function () { buildCustomPanel(); });
         });
       }
 
@@ -352,8 +369,12 @@ export function buildEmojiPicker(opts) {
           delBtn.addEventListener("click", function (e) {
             e.stopPropagation();
             deleteCustomIcon(entry.slug).then(function () {
+              // Same stale-closure hazard as the upload success path above:
+              // buildCustomPanel() already repaints via its own fresh
+              // renderCustomGrid; the closure captured here is orphaned
+              // once buildCustomPanel() rebuilds the panel.
               customList = null;
-              fetchCustomList(function () { buildCustomPanel(); renderCustomGrid(); });
+              fetchCustomList(function () { buildCustomPanel(); });
             });
           });
           tile.appendChild(delBtn);