Function handleAddReaction

desktop/src/testing/e2eBridge.ts:7193–7227

* Mock the `add_reaction` Tauri command. Mirrors the real Rust command: a * kind:7 whose content is the emoji, plus — for a custom emoji — the NIP-30 * `["emoji", shortcode, url]` tag (shortcode normalized to match the relay). * Recorded into the target's channel store and emitted live so the tim

(
  args: { eventId: string; emoji: string; emojiUrl?: string | null },
  config: E2eConfig | undefined,
)

 * kind:7). Unicode reactions carry no emoji tag, like the real command.
 */
async function handleAddReaction(
  args: { eventId: string; emoji: string; emojiUrl?: string | null },
  config: E2eConfig | undefined,
): Promise<void> {
  const channelId = findMockEventChannel(args.eventId);
  if (!channelId) {
    throw new Error(`mock add_reaction: unknown target event ${args.eventId}`);
  }

  const emoji = args.emoji.trim();
  // `h` routes the live event to the channel store (getChannelIdFromTags);
  // `e` names the reaction target. For a custom emoji, the NIP-30
  // `["emoji", shortcode, url]` tag carries the image URL.
  const tags: string[][] = [
    ["h", channelId],
    ["e", args.eventId],
  ];
  if (args.emojiUrl) {
    const shortcode = emoji.replace(/^:+/, "").replace(/:+$/, "").toLowerCase();
    tags.push(["emoji", shortcode, args.emojiUrl]);
  }

  const event = createMockEvent(
    KIND_REACTION,
    emoji,
    tags,
    getMockMemberPubkey(config),
    Math.floor(Date.now() / 1000),
    // 64-hex id so the kind:5 deletion emitted by remove_reaction is accepted
    // by the timeline (getDeletionTargets requires a 64-hex `e` tag).
    mockEventId(),
  );
  recordMockMessage(channelId, event);
  emitMockLiveEvent(channelId, event);
}

/**
 * Mock the `remove_reaction` Tauri command. Finds the active member's own