fix(signal): handle reactions in dataMessage.reaction format (#1)

* fix(signal): handle reactions inside dataMessage.reaction

Signal reactions can arrive in two formats:
1. envelope.reactionMessage (already handled)
2. envelope.dataMessage.reaction (now handled)

The signal-cli SSE events use the second format, which was being
misinterpreted as a message with attachments, leading to 'broken
media / attachments' errors.

Changes:
- Add reaction property to SignalDataMessage type
- Check both envelope.reactionMessage and dataMessage.reaction
- Improve body content detection to properly identify reaction-only messages
- Add test for dataMessage.reaction format

* fix(signal): reaction notifications work when account is phone number

When reactionNotifications mode is 'own', notifications would never fire
because resolveSignalReactionTarget() returned a UUID but
shouldEmitSignalReactionNotification() compared it against the account
phone number, which never matched.

The fix:
- Add optional 'phone' field to SignalReactionTarget type
- Extract phone number first in resolveSignalReactionTarget(), include
  it even when UUID is present
- In shouldEmitSignalReactionNotification() 'own' mode, check phone
  match first before falling back to UUID comparison

This ensures reactions to your own messages are properly detected when
the Signal account is configured as a phone number and the reaction
event contains both targetAuthor (phone) and targetAuthorUuid.

* fix(signal): include phone in reaction target for own-mode matching

When targetAuthorUuid is present, also store targetAuthor phone number
in the reaction target. This allows own-mode reaction notifications to
match when comparing account phone against UUID-based targets.

src/signal/monitor.ts

@@ -70,6 +70,7 @@ type SignalDataMessage = {
     groupName?: string | null;
   } | null;
   quote?: { text?: string | null } | null;
+  reaction?: SignalReactionMessage | null;
 };
 
 type SignalAttachment = {
@@ -403,8 +404,14 @@ export async function monitorSignalProvider(
       }
       const dataMessage =
         envelope.dataMessage ?? envelope.editMessage?.dataMessage;
-      if (envelope.reactionMessage && !dataMessage) {
-        const reaction = envelope.reactionMessage;
+      const reaction =
+        envelope.reactionMessage ?? dataMessage?.reaction ?? null;
+      const messageText = (dataMessage?.message ?? "").trim();
+      const quoteText = dataMessage?.quote?.text?.trim() ?? "";
+      const hasBodyContent =
+        Boolean(messageText || quoteText) ||
+        Boolean(!reaction && dataMessage?.attachments?.length);
+      if (reaction && !hasBodyContent) {
         if (reaction.isRemove) return; // Ignore reaction removals
         const emojiLabel = reaction.emoji?.trim() || "emoji";
         const senderDisplay = formatSignalSenderDisplay(sender);
@@ -550,7 +557,6 @@ export async function monitorSignalProvider(
           ? isSignalSenderAllowed(sender, effectiveGroupAllow)
           : true
         : dmAllowed;
-      const messageText = (dataMessage.message ?? "").trim();
 
       let mediaPath: string | undefined;
       let mediaType: string | undefined;