Fix tests and remove unused import for #675, #673, #672, #690, #693

[UFObject247]

Fix tests, remove dead code, and clean up mock patterns

Closes #669
Closes #691

Description:

• archived-vaults.test.ts (Add GET /api/v1/admin/vaults/archived endpoint #675): Remove unused import * as vault; refactor mocks to use
  vi.mocked(VaultService).mockReturnValue(...) pattern for consistency.
• consistency-total-supply.test.ts (Add GET /api/v1/admin/consistency/total-supply #673): Same mock refactoring â�� replace new VaultService()
  • method mocking with constructor return-value mocking.
• webhooks.test.ts (Write integration tests for webhook registration endpoints #690): Add missing notifications.js mock with validateWebhookUrl;
  include consecutiveFailures field in expected response.
• deposit-indexing.e2e.test.ts (Write end-to-end test for deposit indexing flow #523): Add child: vi.fn().mockReturnThis() to logger mock.
• indexer-lag-alert.test.ts (Add indexer lag alert log when behind chain tip #672): Fix beforeEach to be async; replace require with
  await import; rework "logs error on every tick" test to reset lastLedger each iteration.
• indexer.ts: Remove dead handleOperatorAdded/handleOperatorRemoved methods (duplicates
  of the implementations at lines 887â��945 that accept ParsedOperatorAddedEvent).
• redemption-queue.test.ts: Fix import paths (relative to test location); update XDR API
  calls (xdr.ScAddress instead of xdr.Address, UInt128Parts constructor); align mock
  call order with actual processEvent flow (duplicate check first); update assertion from
  DO NOTHING to DO UPDATE.