feat: captain decides if conversation should be resolved or kept open (#13336)

# Pull Request Template

## Description

captain decides if conversation should be resolved or open

Fixes
https://linear.app/chatwoot/issue/AI-91/make-captain-resolution-time-configurable

Update: Added 2 entries in reporting events:
`conversation_captain_handoff` and `conversation_captain_resolved`

## Type of change

Please delete options that are not relevant.

- [x] New feature (non-breaking change which adds functionality)
- [x] This change requires a documentation update

## How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide
instructions so we can reproduce. Please also list any relevant details
for your test configuration.

LLM call decides that conversation is resolved, drops a private note
<img width="1228" height="438" alt="image"
src="https://github.com/user-attachments/assets/fb2cf1e9-4b2b-458b-a1e2-45c53d6a0158"
/>

LLM call decides conversation is still open as query was not resolved
<img width="1215" height="573" alt="image"
src="https://github.com/user-attachments/assets/2d1d5322-f567-487e-954e-11ab0798d11c"
/>


## Checklist:

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

---------

Co-authored-by: Sojan Jose <sojan@pepalo.com>

app/models/message.rb

@@ -81,6 +81,8 @@ class Message < ApplicationRecord
 
   # when you have a temperory id in your frontend and want it echoed back via action cable
   attr_accessor :echo_id
+  # Transient flag used to skip waiting_since clearing for specific bot/system messages.
+  attr_accessor :preserve_waiting_since
 
   enum message_type: { incoming: 0, outgoing: 1, activity: 2, template: 3 }
   enum content_type: {
@@ -323,20 +325,24 @@ class Message < ApplicationRecord
   end
 
   def update_waiting_since
-    waiting_present = conversation.waiting_since.present?
+    clear_waiting_since_on_outgoing_response if conversation.waiting_since.present? && !private
+    set_waiting_since_on_incoming_message
+  end
 
-    if waiting_present && !private
-      if human_response?
-        Rails.configuration.dispatcher.dispatch(
-          REPLY_CREATED, Time.zone.now, waiting_since: conversation.waiting_since, message: self
-        )
-        conversation.update(waiting_since: nil)
-      elsif bot_response?
-        # Bot responses also clear waiting_since (simpler than checking on next customer message)
-        conversation.update(waiting_since: nil)
-      end
+  def clear_waiting_since_on_outgoing_response
+    if human_response?
+      Rails.configuration.dispatcher.dispatch(
+        REPLY_CREATED, Time.zone.now, waiting_since: conversation.waiting_since, message: self
+      )
+      conversation.update(waiting_since: nil)
+      return
     end
 
+    # Bot responses also clear waiting_since (simpler than checking on next customer message)
+    conversation.update(waiting_since: nil) if bot_response? && !preserve_waiting_since
+  end
+
+  def set_waiting_since_on_incoming_message
     # Set waiting_since when customer sends a message (if currently blank)
     conversation.update(waiting_since: created_at) if incoming? && conversation.waiting_since.blank?
   end