refactor(sybgo): trim Sybgo to 7 lifecycle methods — EPIC #93 complete

[MathieuLamiot]

Description

Removes Sybgo::get_cron_hooks() — the last non-lifecycle method on the class. Uninstaller and deactivate() now call Cron_Manager::get_hooks() directly as the canonical source. Sybgo is reduced to its target 7 methods: get_instance, __construct, get_library_config, init, build_modules, activate, deactivate. EPIC #93 is complete.

Closes #100

Type of change

• New feature (non-breaking change which adds functionality).
• Bug fix (non-breaking change which fixes an issue).
• Enhancement (non-breaking change which improves an existing functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).
• Sub-task of Introduce Feature Modules to own WP integration by domain #93
• Chore
• Release

Detailed scenario

What was tested

No manual testing required — this is a pure identifier redirection. Sybgo::get_cron_hooks() was already delegating to Cron_Manager::get_hooks() in the previous sub-issue (#99), so the hook list returned is identical. The only observable behavior change is that Sybgo::get_cron_hooks() no longer exists as a callable method.

Verified manually by running vendor/bin/phpunit --testsuite Unit after the change: 77 tests executed with the same 5 pre-existing DashboardWidgetTest failures and no new regressions.

How to test

1. Activate the plugin on a WordPress install.
2. Deactivate the plugin — verify all four cron events are unscheduled:

   wp cron event list | grep sybgo

   Expected: no sybgo cron events listed.
3. Uninstall the plugin (delete from WP Admin) — verify no errors in the PHP log.
4. Re-install and run the full unit suite:

   cd wp-plugin && vendor/bin/phpunit --testsuite Unit

   Expected: same pass/fail count as the parent branch (5 pre-existing DashboardWidgetTest failures, all others green).

Affected Features & Quality Assurance Scope

• Plugin deactivation (cron cleanup)
• Plugin uninstall (full data cleanup via Uninstaller)

Technical description

Sybgo::get_cron_hooks() introduced in an earlier sub-issue already delegated entirely to Cron_Manager::get_hooks(). This PR removes the wrapper and updates its two callers:

• Sybgo::deactivate() → Cron_Manager::get_hooks()
• Uninstaller::clear_cron_hooks() → Cron_Manager::get_hooks() (swap use Sybgo\Sybgo for use Sybgo\Cron_Manager)
• UninstallerTest updated to match the new import.

Cron_Manager::get_hooks() was already the canonical source (static method returning all four hook names). The development.md Plugin Uninstall section is updated to reference Cron_Manager::get_hooks() instead of the removed method.

See wp-plugin/docs/development.md.

New dependencies

None.

Risks

None identified. The hook list is identical — the method being removed was a one-line delegation that added no logic.

Mandatory Checklist

Code validation

• I validated all the Acceptance Criteria.
• 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 actionable.

Unticked items justification

N/A — all items apply and are satisfied. No new tests were written because the existing UninstallerTest (updated to use Cron_Manager) already exercises the affected code path.

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.)