test(config): add unit tests for provider module

[aaight]

Summary

Added comprehensive unit tests for the config provider module (src/config/provider.ts) to ensure reliable configuration loading logic.

Card: https://trello.com/c/8AqzAXyf/3-as-a-developer-i-want-unit-tests-for-config-provider-module-so-that-configuration-loading-logic-is-reliable

What was implemented

• Test loadConfig() - Verifies caching behavior and DB repository integration
• Test findProjectByBoardId/Repo/JiraKey - All three lookup functions tested with cache hits and misses
• Test getProjectSecret() - Verifies resolution order (project override → org default), throws on missing secret
• Test getProjectSecretOrNull() - Returns null instead of throwing when secret not found
• Test getProjectSecrets() - Tests bulk credential resolution with caching
• Test getAgentCredential() - Verifies agent-specific credential resolution with proper fallback chain
• Test invalidateConfigCache() - Ensures cache is properly cleared
• 35 test cases covering all functions and edge cases
• 100% code coverage for src/config/provider.ts

Test patterns

• Followed existing patterns from tests/unit/config/configCache.test.ts
• Mocked DB repositories (configRepository, credentialsRepository) and configCache
• Verified cache hits prevent DB calls
• Verified cache misses trigger DB calls and cache updates
• Tested error handling (missing secrets, undefined projects)
• Tested org ID caching and resolution
• Tested agent-specific credential resolution

Testing

• ✅ All 35 new tests passing
• ✅ All existing tests passing (full test suite)
• ✅ 100% coverage for provider.ts
• ✅ Lint checks passing
• ✅ Type checks passing

🤖 Generated with Claude Code