Restructure omni services and add Chatwoot research snapshot

research/chatwoot/app/services/whatsapp/message_dedup_lock.rb

@@ -0,0 +1,19 @@
+# Atomic dedup lock for WhatsApp incoming messages.
+#
+# Meta can deliver the same webhook event multiple times. This lock uses
+# Redis SET NX EX to ensure only one worker processes a given source_id.
+class Whatsapp::MessageDedupLock
+  KEY_PREFIX = Redis::RedisKeys::MESSAGE_SOURCE_KEY
+  DEFAULT_TTL = 1.day.to_i
+
+  def initialize(source_id, ttl: DEFAULT_TTL)
+    @key = format(KEY_PREFIX, id: source_id)
+    @ttl = ttl
+  end
+
+  # Returns true when the lock is acquired (caller should proceed).
+  # Returns false when another worker already holds the lock.
+  def acquire!
+    ::Redis::Alfred.set(@key, true, nx: true, ex: @ttl)
+  end
+end