feat: minimal MailerLite addon — sync pipeline + per-form config + resync action

[jurnskie]

This is the v1.0 marketplace release shape, rebuilt per colleague review:

"Basis was prima, alleen die formconfig dingen moesten anders."

The basis (sync job + listener + MailerLite SDK wrapper + per-form blueprint
section) is preserved. The over-engineering generated during exploration
(dashboard, activity log surface, retry controller + rate limiter, central
form-config repository, custom CP routes/permissions/nav, Vue/Inertia pages)
has been removed. Re-sync is delivered as a Statamic native Submission Action
that appears on the form's built-in submissions list — one button, no
parallel CP surface.

Per-form config is read DIRECTLY from each form's own YAML via
Form::find($handle)->get('enabled' | 'mappings' | 'groups'). No addon-side
mirror, no central form-config repository. Statamic's Form::appendConfigFields
already persists the values where Statamic looks for them.

Components:

src/AddonSettings.php
Thin wrapper around Statamic's native addon-settings store. Single
responsibility: read the API key. Container-bound singleton; tests
replace via app()->instance().

src/MailerLite/MailerLiteService.php + Contracts/, Exceptions/
SDK wrapper. upsertSubscriber(), ping(), listFields(), listGroups().
Translates SDK exceptions to addon-namespace types so the rest of the
addon doesn't depend on the SDK's surface.

src/Sync/SyncSubscriberJob.php
Queued upsert. Reads the API key from AddonSettings and the per-form
mappings/groups directly off the form blueprint. tries=3, backoff=
[60,300,900]. 4xx -> permanent_failure (no retry); 5xx -> transient
(Laravel retries). The finally block emits a Log::info breadcrumb but
does not maintain a separate activity store.

src/Listeners/FormSubmittedListener.php
Captures the visitor IP onto the submission pre-persist.

src/Listeners/SubmissionCreatedListener.php
Thin dispatch gate — reads enabled from the form, dispatches the
job. No driver dependency, no form-config repository.

src/Actions/ResyncToMailerLite.php
Statamic Submission Action (auto-discovered from src/Actions/). Visible
on the form's submissions list when the form has MailerLite sync
enabled. Dispatches a fresh SyncSubscriberJob per selected submission.

src/Fieldtypes/MailerLite{Field,Group}Fieldtype.php
Live-fetched dropdowns. Per-request cache keyed by sha256(api_key)
keeps the SDK call count to one per CP render.

src/StatamicMailerLiteServiceProvider.php
Bindings (AddonSettings singleton + MailerLiteService via interface)
and the per-form MailerLite section append. Listeners and the Action
auto-discover from their respective folders.

resources/blueprints/settings.yaml
Statamic native addon-settings blueprint — API key field. Rendered
under Tools → Addons → MailerLite.

Removed (vs the exploratory PR #3 history on f/js/gsd-mailerlite):

• StorageDriverInterface + AddonYamlDriver (and the FormConfig methods).
  Per-form config now lives where Statamic stores it natively, not
  mirrored into addon storage.
• ActivityLogger, ActivityLogEntry, ActivityLogStore (JSONL).
• All four CP/* controllers (Dashboard, Activity, Retry, FormHealthSummary).
• PruneActivityLogCommand.
• FormSavedListener (the mirror writer).
• Custom CP routes, top-level nav, configure-mailerlite permission,
  retry rate limiter.
• Vue/Inertia Dashboard + Activity pages and the Vite build pipeline.

Quality gates:

Pest 124/124 · PHPStan level 5 clean · Pint clean.

Co-Authored-By: Claude Opus 4.7 noreply@anthropic.com