chore: Add region option to Dialogflow integration (#11510)

## Summary
- support region option when configuring Dialogflow integration
- connect to region endpoint when set
- use session identification based on the region

Fixes: https://github.com/chatwoot/chatwoot/issues/4129

lib/integrations/dialogflow/processor_service.rb

@@ -65,13 +65,37 @@ class Integrations::Dialogflow::ProcessorService < Integrations::BotProcessorSer
     ::Google::Cloud::Dialogflow::V2::Sessions::Client.configure do |config|
       config.timeout = 10.0
       config.credentials = hook.settings['credentials']
+      config.endpoint = dialogflow_endpoint
     end
   end
 
+  def normalized_region
+    region = hook.settings['region'].to_s.strip
+    (region.presence || 'global')
+  end
+
+  def dialogflow_endpoint
+    region = normalized_region
+    return 'dialogflow.googleapis.com' if region == 'global'
+
+    "#{region}-dialogflow.googleapis.com"
+  end
+
   def detect_intent(session_id, message)
     client = ::Google::Cloud::Dialogflow::V2::Sessions::Client.new
-    session = "projects/#{hook.settings['project_id']}/agent/sessions/#{session_id}"
+    session = build_session_path(session_id)
     query_input = { text: { text: message, language_code: 'en-US' } }
     client.detect_intent session: session, query_input: query_input
   end
+
+  def build_session_path(session_id)
+    project_id = hook.settings['project_id']
+    region = normalized_region
+
+    if region == 'global'
+      "projects/#{project_id}/agent/sessions/#{session_id}"
+    else
+      "projects/#{project_id}/locations/#{region}/agent/sessions/#{session_id}"
+    end
+  end
 end