fix(todo): comments handled as Todoist's, and the emoji sheet (ADR 0033, D38)

After the developer's recording of Todoist: the bar opens the comments to
write at once, Show all to read; the heading folds them; Show all and the
latest comment are boxes of their own; a comment shows who wrote it; the
field grows with what wraps, which a long line didn't.

The emoji sheet is written here on emoji_picker_flutter's data: its own
picker has a tab bar on the SDK's Material, which found no localizations
in Todo, so reacting showed an error. Todo gets the compatibility bridge,
as Learn has, since the editor still imports that library.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/todo/halkyon_todo_flutter/lib/l10n/app_en.arb

@@ -126,6 +126,17 @@
       }
     }
   },
+  "emojiSearch": "Search emoji",
+  "emojiNone": "No emoji found",
+  "emojiRecent": "Recently used",
+  "emojiSmileys": "Smileys & people",
+  "emojiAnimals": "Animals & nature",
+  "emojiFoods": "Food & drink",
+  "emojiActivities": "Activities",
+  "emojiTravel": "Travel & places",
+  "emojiObjects": "Objects",
+  "emojiSymbols": "Symbols",
+  "emojiFlags": "Flags",
   "commentsTitle": "Comments",
   "commentAdd": "Add a comment",
   "commentSend": "Send comment",