fix(whatsapp): ack reaction logic for group activation 'always' mode

- Fix bug where ack reaction was not sent when group activation is 'always'
- When requireMention=false (activation: always), always send reaction
- Add test case for activation='always' scenario
- Update inline comments for clarity

src/web/auto-reply.ts

@@ -1405,7 +1405,9 @@ export async function monitorWebProvider(
             conversationId,
           });
           const requireMention = activation !== "always";
-          if (!requireMention) return false;
+          // If mention is not required (activation === "always"), always react
+          if (!requireMention) return true;
+          // Otherwise, only react if bot was mentioned
           return msg.wasMentioned === true;
         }
         return false;