Escalation email system up

[Fernando-Colimon]

Describe your changes

Adds escalation support to monitor notifications. When a monitor goes down and the
incident remains unacknowledged, an escalation notification is sent to a separate
channel after a configurable delay.

Changes include:

• Added escalation: { delayMinutes, channelId } field to the monitor-notification
  config (Mongoose schema + migration)
• Implemented escalation scheduling in SuperSimpleQueueHelper using BullMQ delayed
  jobs with deterministic job IDs to prevent duplicates
• Escalation job is automatically cancelled when an incident is resolved or
  acknowledged before the delay elapses
• Added escalationJobId to incident documents so the pending job can be cancelled
  on manual resolution
• Extracted shared BullMQ Redis connection config into src/config/redis.ts
• Added escalation field to monitor PATCH validation and repository mapper so
  settings are persisted and returned correctly
• Added UI panel in monitor settings to configure escalation rules per monitor
  (toggle, delay input, channel selector with inline validation)

Write your issue number after "Fixes "

Fixes #

Please ensure all items are checked off before requesting a review.

• I deployed the application locally.
• I have performed a self-review and testing of my code.
• I have included the issue # in the PR.
• [x ] I have added i18n support to visible strings
• I have not included any files that are not related to my pull request
• I didn't use any hardcoded values
• I made sure font sizes, color choices etc are all referenced from the theme.
• My PR is granular and targeted to one specific feature.
• I ran npm run format in server and client directories.
• I took a screenshot or a video and attached to this PR if there is a UI change.