Enhancement/8094 managing api failure

[Miraeld]

Description

Fixes #8094
After completing the RocketCDN express checkout, users may encounter situations where the subscription activation fails. This PR adds two recovery mechanisms:

1. Admin Notice: When activation fails without CDN configuration (is_active=false, cdn_url empty), displays a notice with a link to retry activation via express checkout.
2. Auto-Retry: When activation fails but CDN URL exists (is_active=false, cdn_url exists), automatically retries activation on next admin page load.

This prevents users from getting stuck with incomplete RocketCDN subscriptions after checkout.

Type of change

• Enhancement (non-breaking change which improves an existing functionality).

Detailed scenario

What was tested

Automated Testing:

• 7 integration tests for activation failed notice (all edge cases: capability checks, screen checks, white label, active subscriptions, etc.)
• 7 integration tests for auto-retry activation (all scenarios: token validation, API failures, successful retry)
• All 14 tests passing

Manual Testing:

• Verified notice displays when is_active=false and cdn_url is empty
• Verified auto-retry triggers when is_active=false but cdn_url exists
• Verified notice includes correct express checkout URL
• Verified notice respects white label settings

How to test

Needs API errors.

Affected Features & Quality Assurance Scope

Direct Impact:

• RocketCDN activation flow
• RocketCDN admin notices
• WP Rocket Settings page (admin notices display)

QA Testing Scope:

• RocketCDN express checkout completion
• RocketCDN activation scenarios (success, failure, partial failure)
• Admin notice display logic
• White label account behavior (notices should not display)
• User capability checks (non-admin users should not see notices)

Technical description

Documentation

Flow Diagram:

Express Checkout Complete
          ↓
   Get Subscription Status
          ↓
    ┌──────────────┐
    │ is_active?   │
    └──────┬───────┘
           │
     ┌─────┴─────┐
     No         Yes → All good!
     │
     ↓
┌─────────────┐
│ has cdn_url?│
└─────┬───────┘
      │
  ┌───┴────┐
  No      Yes
  │        │
  ↓        ↓
Show     Auto-retry
Notice   Activation

Implementation:

• NoticesSubscriber::activation_failed_notice(): Displays admin notice when subscription is inactive without CDN URL. Reads express checkout URL from UserClient API.

• DataManagerSubscriber::maybe_retry_activation(): Fires on admin_init, checks if subscription has CDN URL but is_active=false, then calls APIClient to retry activation via PATCH request.

• Both methods share subscription status checks via APIClient::get_subscription_data() which reads from rocketcdn_status transient.

Mandatory Checklist

Code validation

• I validated all the Acceptance Criteria. If possible, provide screenshots or videos.
• I triggered all changed lines of code at least once without new errors/warnings/notices.
• I implemented built-in tests to cover the new/changed code.

Code style

• I wrote a self-explanatory code about what it does.
• I protected entry points against unexpected inputs.
• I did not introduce unnecessary complexity.
• Output messages (errors, notices, logs) are explicit enough for users to understand the issue and are actionnable.

Unticked items justification

N/A - All items completed.

Additional Checks

• In the case of complex code, I wrote comments to explain it.
• When possible, I prepared ways to observe the implemented system (logs, data, etc.).
• I added error handling logic when using functions that could throw errors (HTTP/API request, filesystem, etc.)

[wordpressfan]

Important point to be handled

[wordpressfan]

@Miraeld plz fix conflicts and send it to QA
Thanks.

[Miraeld]

@Mai-Saad