Restructure omni services and add Chatwoot research snapshot

research/chatwoot/spec/services/whatsapp/message_dedup_lock_spec.rb

@@ -0,0 +1,43 @@
+require 'rails_helper'
+
+describe Whatsapp::MessageDedupLock do
+  let(:source_id) { "wamid.test_#{SecureRandom.hex(8)}" }
+  let(:lock) { described_class.new(source_id) }
+  let(:redis_key) { format(Redis::RedisKeys::MESSAGE_SOURCE_KEY, id: source_id) }
+
+  after { Redis::Alfred.delete(redis_key) }
+
+  describe '#acquire!' do
+    it 'returns truthy on first acquire' do
+      expect(lock.acquire!).to be_truthy
+    end
+
+    it 'returns falsy on second acquire for the same source_id' do
+      lock.acquire!
+      expect(described_class.new(source_id).acquire!).to be_falsy
+    end
+
+    it 'allows different source_ids to acquire independently' do
+      lock.acquire!
+      other = described_class.new("wamid.other_#{SecureRandom.hex(8)}")
+      expect(other.acquire!).to be_truthy
+    end
+
+    it 'lets exactly one thread win when two race for the same source_id' do
+      results = Concurrent::Array.new
+      barrier = Concurrent::CyclicBarrier.new(2)
+
+      threads = Array.new(2) do
+        Thread.new do
+          barrier.wait
+          results << described_class.new(source_id).acquire!
+        end
+      end
+
+      threads.each(&:join)
+
+      wins = results.count { |r| r }
+      expect(wins).to eq(1), "Expected exactly 1 winner but got #{wins}. Results: #{results.inspect}"
+    end
+  end
+end