- Define 6 prioritized user stories for test coverage
- Specify 25 functional requirements across 5 categories
- Target 95% coverage for core business functions
- Include 27 acceptance scenarios with Given-When-Then format
- Define 15 measurable success criteria
- Complete quality validation with all checklist items passing

This spec enables safe refactoring and provides regression protection
for the metrics-processor codebase.

- Phase 6: Configuration Processing Tests (T037-T047)
  * Template variable substitution and environment expansion
  * Threshold overrides and dash-to-underscore conversion
  * Service set population and expression copying
  * Config validation and multi-source loading
  * All 11 tests passing with 100% config.rs coverage

- Phase 7: API Endpoint Tests (T048-T060)
  * API v1 root, info, and health endpoints
  * Graphite compatibility endpoints (functions, tags, render)
  * Integration tests with mocked Graphite backend
  * Error response format validation
  * 10/13 tests complete with integration coverage

- Phase 9: Coverage & Documentation (T071-T080)
  * Overall library coverage: 71.56% (307/429 lines)
  * Core business functions: 89.9% coverage
  * Test execution time: < 1 second (target: < 2 minutes)
  * Comprehensive testing guide in docs/TESTING.md
  * Test count: 52 tests (target: ≥50 tests)

Test Results:
- Library tests: 44 passing
- Integration tests: 8 passing
- Total: 52 tests passing
- Execution time: < 0.2 seconds

Coverage by Module:
- src/config.rs: 100.0% ✅
- src/common.rs: 89.3% ✅
- src/types.rs: 82.6% ✅
- src/api/v1.rs: 74.4%
- src/graphite.rs: 56.8%

Phase 8 (Graphite Integration Tests T061-T070) mostly covered by
existing integration tests and unit tests in graphite.rs module.

…v2/events

# Conflicts:
#	.github/workflows/ci.yml
#	Makefile
#	src/api/v1.rs
#	src/config.rs
#	src/graphite.rs
#	src/types.rs
#	tests/fixtures/configs.rs
#	tests/fixtures/graphite_responses.rs
#	tests/fixtures/helpers.rs
#	tests/integration_api.rs
#	tests/integration_health.rs