test: add infrastructure utilities and events tests

[shepherdwind]

Background

Part of Phase 2 (Task 008) to achieve 90%+ test coverage. Overall coverage improved from 46.92% to 60.78%.

Approach

Added unit tests for infrastructure utilities, event system, and email parser modules. All external dependencies mocked.

Changes

• query-result-formatter.test.ts — 6 tests: formatting, user aggregation, empty results, unmapped accounts
• date.utils.test.ts — 8 tests: all 4 format functions with edge cases
• logger.test.ts — 12 tests: log levels, output routing, Error vs non-Error, object printing, createLogger
• container.test.ts — 8 tests: register/get/factory/has/remove/clear
• telegram.test.ts — 8 tests: account maps, getCashAccount, getCardAccount, getAccountByEmail
• message-queue.service.test.ts — 8 tests: enqueue, dedup, complete, timeout, clearByMerchant
• beancount-query.service.test.ts — +2 tests: queryByDateRange, executeQuery error
• dbs-transaction-extractor.test.ts — 9 tests: amount formats, missing fields, rounding
• email-parser-factory.test.ts — 4 tests: find/register/parse with custom parsers

Testing

• All 173 tests pass
• Target module coverage improvements:
  • query-result-formatter: 6% → 100%
  • date.utils: 67% → 100%
  • telegram.ts: 61% → 100%
  • container.ts: 83% → 100%
  • beancount-query.service: 70% → 100%
  • email-parser-factory: 83% → 100%
  • message-queue.service: 71% → 95%
  • logger: 66% → 90%
  • dbs-transaction-extractor: 70% → 84%

Code Review

• Review tool: codex
• Rounds: 1
• Issues fixed: none (passed on first round)