Webhook event replay re deliver past events by time range

[clintjeff2]

Motivation

• Provide a way to re-deliver past system events for a given webhook when subscribers were unavailable.
• Persist recent published events in-memory so replays can be requested by time window.
• Ensure replays respect a webhook's registered events and reuse the existing delivery path.

Description

• Add a bounded in-memory event log (globalThis.__openStellarEventLog__) capped at 500 entries and helper APIs listPublishedSystemEvents() and resetPublishedSystemEventLogForTests() in lib/events/system-events.ts.
• Implement replayEventsToWebhook(webhookId, from, to) in lib/webhooks/delivery.ts which looks up the webhook, filters the persisted events by occurredAt window and webhook events, and calls the existing deliverToWebhook() for each match.
• Add POST /api/webhooks/[id]/replay at app/api/webhooks/[id]/replay/route.ts with strict ISO timestamp validation for from/to, from <= to checks, returns { ok: true, queued: number }, and returns 404 when the webhook is not found.
• Update OpenAPI metadata at app/api/openapi.json/route.ts and add unit tests in __tests__/api/webhooks.test.ts covering zero-event replay, type-filtered replay, full-window replay, unknown webhook 404, and ring-buffer eviction behavior.

Testing

• Ran unit tests: vitest for __tests__/api/webhooks.test.ts and __tests__/api/openapi.test.ts — both test files passed.
• Ran targeted ESLint on modified files — lint checks for changed files passed; full repo npm run lint reported pre-existing unrelated issues in other files.
• Attempted npm run build — failed in this environment due to Next.js failing to fetch Google Fonts (unrelated to these changes).

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Closes #245

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[clintjeff2]

@leocagli, review and merge.

[clintjeff2]

@leocagli, review and merge.

[clintjeff2]

@leocagli, review and merge.

[clintjeff2]

@leocagli, review and merge.

[clintjeff2]

@leocagli, please review and merge.