feat: captain should be able to access private notes (#11768)

# Pull Request Template

## Linear task: 

https://linear.app/chatwoot/issue/CW-4482/captain-should-be-able-to-access-private-notes-only-on-copilot

## Description

Captain should be able to access private notes (only on copilot)

## Type of change

- [x] New feature (non-breaking change which adds functionality)

## How Has This Been Tested?


![image](https://github.com/user-attachments/assets/b25cf81f-85eb-4adb-a1eb-57e1156b9b9e)


![image](https://github.com/user-attachments/assets/20051b31-cbce-41d9-84d9-13bc71687323)


## Checklist:

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

---------

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/services/llm_formatter/conversation_llm_formatter.rb

@@ -5,7 +5,7 @@ class LlmFormatter::ConversationLlmFormatter < LlmFormatter::DefaultLlmFormatter
     sections << "Channel: #{@record.inbox.channel.name}"
     sections << 'Message History:'
     sections << if @record.messages.any?
-                  build_messages
+                  build_messages(config)
                 else
                   'No messages in this conversation'
                 end
@@ -23,11 +23,16 @@ class LlmFormatter::ConversationLlmFormatter < LlmFormatter::DefaultLlmFormatter
 
   private
 
-  def build_messages
+  def build_messages(config = {})
     return "No messages in this conversation\n" if @record.messages.empty?
 
     message_text = ''
-    @record.messages.chat.order(created_at: :asc).each do |message|
+    messages = @record.messages.where.not(message_type: :activity).order(created_at: :asc)
+
+    messages.each do |message|
+      # Skip private messages unless explicitly included in config
+      next if message.private? && !config[:include_private_messages]
+
       message_text << format_message(message)
     end
     message_text
@@ -35,6 +40,7 @@ class LlmFormatter::ConversationLlmFormatter < LlmFormatter::DefaultLlmFormatter
 
   def format_message(message)
     sender = message.message_type == 'incoming' ? 'User' : 'Support agent'
+    sender = "[Private Note] #{sender}" if message.private?
     "#{sender}: #{message.content}\n"
   end