Implement Contract/Feature Tests (T002-T022) for Dynamic Reload & Health Aggregation Features

[Copilot]

This PR implements the Contract/Feature Tests phase (T002-T022) from the tasks.md specification for dynamic reload, health aggregation, and related framework enhancements. These are intentionally failing tests (TDD RED phase) that define comprehensive contracts for upcoming implementations.

What's Implemented

Core Framework Contracts (T002-T017)

• Dynamic Reload System (T002-T004): Tests for Reloadable interface, dynamic vs static field detection, and atomic reload operations
• Health Aggregation (T005-T006): Tests for HealthAggregator with optional service exclusion and status precedence rules
• Service Registry Enhancements (T007, T010): Tests for ServiceScope enum and tie-break ambiguity resolution
• Tenant Management (T008, T011): Tests for TenantGuardMode and isolation leak prevention
• Decorator Ordering (T009): Tests for priority metadata and tie-break resolution
• Concurrency Safety (T012): Tests for reload race safety with atomic operations
• Health Timing (T013): Tests for jitter configuration and timing accuracy
• Metrics Integration (T014): Tests for reload/health metrics emission
• Error Taxonomy (T015): Tests for consistent error classification and handling
• Secret Management (T016-T017): Tests for secret redaction in logging and provenance tracking

Module-Specific Contracts (T018-T022)

• Scheduler Module (T018): Tests for bounded catch-up policies to prevent resource exhaustion
• Let's Encrypt Module (T019): Tests for ACME escalation events and monitoring
• Auth Module (T020-T022): Tests for OIDC SPI multi-provider support, authentication mechanism coexistence, and error taxonomy integration

Key Features

Interface Definitions

// Example interfaces defined by the tests
type Reloadable interface {
    Reload(config interface{}) error
    IsReloadInProgress() bool
}

type HealthAggregator interface {
    CheckReadiness() (bool, []string)
    CheckLiveness() (bool, []string)
    RegisterHealthReporter(name string, reporter interface{}, optional bool) error
}

type ServiceScope int
const (
    ServiceScopeApplication ServiceScope = iota
    ServiceScopeModule
    ServiceScopeTenant
    ServiceScopeInstance
)

Builder Pattern Support

Tests define new builder options like:

• WithDynamicReload() for reload pipeline configuration
• WithHealthAggregator() for health monitoring setup
• WithTenantGuardMode() for tenant isolation controls
• WithOIDCProvider() for authentication provider registration

Observer Event Contracts

Tests expect these events to be emitted:

• ConfigReloadStarted, ConfigReloadCompleted, ConfigReloadFailed
• HealthEvaluated with status change information
• CertificateRenewalEscalated for ACME monitoring

Test Structure

• 21 test files with 200+ individual test cases
• Internal tests (internal/) for core framework features
• Module tests (modules/*/) for module-specific functionality
• Proper separation between CORE and MODULE responsibilities
• Comprehensive coverage of success paths, error conditions, edge cases, and security requirements

TDD RED Phase Validation

All tests are designed to fail initially with meaningful error messages:

=== FAIL: TestHealthIntervalJitter/health_ticker_should_support_jitter_configuration (0.00s)
    health_interval_jitter_test.go:27: Expected value not to be nil.
        Messages: HealthTicker interface should be defined
    health_interval_jitter_test.go:30: Health interval jitter not implemented - 
        this test should pass once T048 is implemented

This follows TDD best practices where failing tests define the contracts before implementation begins.

Recent Changes

• Removed duplicate tasks.md file from repository root (kept the one in specs/001-baseline-specification-for/)

Next Steps

Phase 3.3 (GREEN) will implement the actual functionality to make these tests pass, following the interfaces and contracts defined here. The implementation will be guided by these comprehensive test specifications to ensure correct behavior, proper error handling, security, and performance requirements.

Created from VS Code via the GitHub Pull Request extension.

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