refactor: consolidate Tool interface and eliminate SOLID principle violations

This comprehensive refactoring addresses multiple SOLID principle violations and consolidates the tool architecture:

**SOLID Principle Fixes:**
- **Single Responsibility**: Eliminate hardcoded values by extracting constants and configuration providers
- **Open/Closed**: Remove switch statements in favor of polymorphic tool implementations
- **Interface Segregation**: Consolidate URLProvider and ChecksumProvider into cohesive Tool interface
- **Dependency Inversion**: Abstract configuration access through provider interfaces

**Key Architectural Changes:**
- **Tool Interface Consolidation**: Merge URL generation and checksum verification methods directly into Tool interface, eliminating interface proliferation anti-pattern
- **Constants Extraction**: Centralize magic numbers, timeouts, and URLs in constants.go
- **Configuration Providers**: Abstract environment variable access through ConfigProvider interfaces
- **Platform Abstraction**: Add PlatformMapper for cross-platform binary handling
- **Path Resolution**: Implement PathResolver utilities for consistent tool path management
- **Error Handling**: Standardize error types and wrapping across all tools

**Tool Implementation Updates:**
- **Maven/Mvnd**: Add GetChecksum methods with Apache archive SHA512 verification
- **Node.js**: Enhance SHASUMS256.txt parsing with better error handling
- **Java**: Integrate Foojay Disco API checksum verification
- **Go**: Maintain existing go.dev API integration
- **All Tools**: Implement unified URL generation and checksum verification methods

**Command System Simplification:**
- Replace tool-specific switch statements with polymorphic manager methods
- Consolidate search, validation, and info commands through unified Tool interface
- Eliminate 300+ lines of duplicated tool-specific command handling code

**Download System Integration:**
- Update DownloadConfig to use Tool interface directly for checksum verification
- Remove dependency on separate ChecksumRegistry and URLProvider registrations
- Simplify verification flow through direct tool method calls

**Benefits:**
- **Maintainability**: Related functionality stays together in cohesive interfaces
- **Extensibility**: New tools require zero changes to existing command/download code
- **Testability**: Each tool's functionality can be tested independently
- **Consistency**: Standardized patterns across all tool implementations
- **Simplicity**: Fewer abstractions, clearer design, easier to understand

This refactoring transforms the codebase from an anti-pattern heavy design with interface proliferation and switch statement violations into a clean, SOLID-compliant architecture with proper separation of concerns.

Author: gnodet

cmd/root.go

@@ -55,8 +55,9 @@ For more information, visit: https://github.com/gnodet/mvx`,
 func Execute() error {
 	// Auto-setup tools and environment before executing any command
 	if err := autoSetupEnvironment(); err != nil {
-		// Don't fail completely if auto-setup fails, but warn the user
-		printVerbose("Auto-setup failed: %v", err)
+		// If auto-setup fails, we should fail the command execution
+		// This prevents commands from running with missing tools
+		return fmt.Errorf("auto-setup failed: %w", err)
 	}
 
 	// Add dynamic custom commands before execution