feat: Add support for minutes in auto resolve feature (#11269)

### Summary

- Converts conversation auto-resolution duration from days to minutes
for more
granular control
- Updates validation to allow values from 10 minutes (minimum) to 999
days (maximum)
- Implements smart messaging to show appropriate time units in activity
messages

###  Changes

- Created migration to convert existing durations from days to minutes
(x1440)
- Updated conversation resolver to use minutes instead of days
- Added dynamic translation key selection based on duration value
- Updated related specs and documentation
- Added support for displaying durations in days, hours, or minutes
based on value

###  Test plan

- Verify account validation accepts new minute-based ranges
- Confirm existing account settings are correctly migrated
- Test auto-resolution works properly with minute values
- Ensure proper time unit display in activity messages

---------

Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>

app/services/message_templates/template/auto_resolve.rb

@@ -0,0 +1,25 @@
+class MessageTemplates::Template::AutoResolve
+  pattr_initialize [:conversation!]
+
+  def perform
+    return if conversation.account.auto_resolve_message.blank?
+
+    ActiveRecord::Base.transaction do
+      conversation.messages.create!(auto_resolve_message_params)
+    end
+  end
+
+  private
+
+  delegate :contact, :account, to: :conversation
+  delegate :inbox, to: :message
+
+  def auto_resolve_message_params
+    {
+      account_id: @conversation.account_id,
+      inbox_id: @conversation.inbox_id,
+      message_type: :template,
+      content: account.auto_resolve_message
+    }
+  end
+end