Add sender recovery campaign preset

[Errordog2]

Summary

• add a deterministic sender recovery campaign preset for unknown senders, paid requests, approvals, blocks, and refund education
• include fake request-state outcomes and one safe @stealth.demo draft per state
• add validation and summary helpers plus focused tests for statuses, safe recipients, fake-data copy, and validation errors

Closes #270

Validation

px prettier --check src/features/demo-admin-dashboard/fixtures/senderRecoveryCampaignPreset.ts src/features/demo-admin-dashboard/tests/senderRecoveryCampaignPreset.test.ts src/features/demo-admin-dashboard/index.ts

• git diff --check
• sensitive scan for account/payment/private-key markers returned no matches

px vitest run src/features/demo-admin-dashboard/tests/senderRecoveryCampaignPreset.test.ts could not start locally because this fresh checkout is missing the Vite config packages (@cloudflare/vite-plugin, @tailwindcss/vite, @tanstack/react-start/plugin/vite, @vitejs/plugin-react, �ite, �ite-tsconfig-paths)