Add comprehensive test suite for current implementation

- Add tests for internal/config package (90.9% coverage)
  - Test all viperConfig getter methods
  - Test LoadConfig with default and environment-specific configs
  - Test error handling for missing config files

- Add tests for internal/di package (88.1% coverage)
  - Test Container lifecycle (NewContainer, Start, Stop)
  - Test providers (ProvideConfig, ProvideLogger, CoreModule)
  - Test lifecycle hooks registration
  - Include mock implementations for testing

- Add tests for internal/logger package (96.5% coverage)
  - Test zapLogger with JSON and console formats
  - Test all logging levels and methods
  - Test middleware (RequestIDMiddleware, LoggingMiddleware)
  - Test context helper functions
  - Include benchmark tests

- Update CI workflow to skip tests when no test files exist
  - Add conditional test execution based on test file presence
  - Add timeout for test execution
  - Verify build when no tests are present

All tests follow Go best practices with table-driven patterns,
parallel execution where safe, and comprehensive coverage.

internal/logger/middleware.go

@@ -3,9 +3,9 @@ package logger
 import (
 	"context"
 
+	"git.dcentral.systems/toolz/goplt/pkg/logger"
 	"github.com/gin-gonic/gin"
 	"github.com/google/uuid"
-	"git.dcentral.systems/toolz/goplt/pkg/logger"
 )
 
 const (