upcoming: [DI-28773] - Support to select system channel based on service type controlled by LD flag

[venkymano-akamai]

Description 📝

Allow to select system notification channel while creating / editing alert based on the service type selected controlled through LD flag

Changes 🔄

1. New LD flag under aclpAlerting - systemChannelSupportedServices which holds the service type for which to support adding system notification channels
2. Reset channel ids if service type is changed.
3. Disable Add Notification Channel button if service type is not selected
4. In AddChannelListing use the LD to show whether to allow selecting system channel or not.

Scope 🚢

Upon production release, changes in this PR will be visible to:

• All customers
• Some customers (e.g. in Beta or Limited Availability)
• No customers / Not applicable

Target release date 🗓️ (Next release)

25-12-2025 inside linode develop branch

Preview 📷

Before	After

How to test 🧪

1. Login as mock
2. Navigate to Monitor and then to Alerts
3. Click on create alert
4. You should see Add Notification Channel disabled when service type is not selected
5. Once you select the service type, inside the drawer you see channels grouped by System and User
6. If LD supports only linode, to achieve this in line number of 68 of AddChannelListing you can use the following
   flags.aclpAlerting?.systemChannelSupportedServices ?? ['linode'];
7. Now for the rest of services , you will not be able to see system channels

Author Checklists

As an Author, to speed up the review process, I considered 🤔

👀 Doing a self review
❔ Our contribution guidelines
🤏 Splitting feature into small PRs
➕ Adding a changeset
🧪 Providing/improving test coverage
🔐 Removing all sensitive information from the code and PR description
🚩 Using a feature flag to protect the release
👣 Providing comprehensive reproduction steps
📑 Providing or updating our documentation
🕛 Scheduling a pair reviewing session
📱 Providing mobile support
♿ Providing accessibility support

• I have read and considered all applicable items listed above.

As an Author, before moving this PR from Draft to Open, I confirmed ✅

• All tests and CI checks are passing
• TypeScript compilation succeeded without errors
• Code passes all linting rules

[linode-gh-bot]

Cloud Manager UI test results

🎉 867 passing tests on test run #4 ↗︎

❌ Failing	✅ Passing	↪️ Skipped	🕐 Duration
0 Failing	867 Passing	11 Skipped	50m 48s