refactor: comprehensive cleanup and interface improvements

[gnodet]

Overview

This PR performs a comprehensive cleanup of deprecated/unused code and improves the Tool interface design, resulting in a significantly cleaner and more maintainable codebase.

Changes Made

🧹 Removed Deprecated/Unused Code

Deprecated Installation Methods:

• ❌ Removed InstallTool(), InstallTools(), InstallToolsParallel(), InstallToolsWithOptions()
• ❌ Removed unused InstallOptions struct
• ✅ Updated all callers to use EnsureTools()/EnsureTool() instead

Redundant Tool Methods:

• ❌ Removed redundant Name() methods from all tools
• ✅ Consolidated on GetToolName() for consistency

Deprecated Config Fields:

• ❌ Removed deprecated Pre/Post hook fields from CommandConfig
• These were part of the old built-in command system that was replaced with user-defined custom commands

Unused Cache Methods:

• ❌ Removed ClearAllCaches(), ClearPathCache() methods
• ❌ Removed unused CacheManager interface

🔧 Enhanced GetChecksum Interface

Before:

GetChecksum(version, filename string) (ChecksumInfo, error)

After:

GetChecksum(version string, cfg config.ToolConfig, filename string) (ChecksumInfo, error)

Benefits:

• Tools now have access to full ToolConfig including distribution info and options
• Enables more efficient and context-aware checksum fetching
• Java can now use cfg.Distribution to target specific distributions (temurin, zulu, etc.)
• More consistent and extensible interface across all tools

🧹 Removed Unused Internal Methods

Removed from all tools:

• getVersionsURL() - Not used anywhere in the codebase
• getChecksumURL() from JavaTool, GoTool, NodeTool - Not actually called

Kept where actually used:

• getChecksumURL() in MavenTool and MvndTool - Still called by their GetChecksum() methods

🔍 Interface Simplification

Eliminated Entire Interface:

• ❌ Removed ToolMetadataProvider interface entirely
• ✅ Moved GetDisplayName() into main Tool interface
• ❌ Removed GetEmoji() method (using default emoji "📦" in display code)

Made Implementation Details Private:

• ❌ Made GetChecksumURL() and GetVersionsURL() private (lowercase) where not used
• Better encapsulation of internal implementation details

📋 Updated All Tool Implementations

• ✅ JavaTool: Updated signature, clarified checksum architecture, removed unused methods
• ✅ GoTool: Updated signature, removed unused methods
• ✅ NodeTool: Updated signature, removed unused methods
• ✅ MavenTool: Updated signature, removed unused getVersionsURL
• ✅ MvndTool: Updated signature, removed unused getVersionsURL

🔍 Java Checksum Architecture Clarification

Java has a different checksum architecture than other tools:

Other Tools (Go, Node, Maven, Mvnd):

• GetChecksum() fetches checksums dynamically when needed
• Called by download.go during download verification

Java Tool:

• Checksums are fetched during installation via getDownloadURLWithChecksum()
• Checksums are added to configuration and used during download
• GetChecksum() returns informative error since checksums are pre-fetched
• More efficient integration with Disco API during URL resolution

Files Changed

• cmd/root.go - Updated to use EnsureTools instead of deprecated methods
• cmd/setup.go - Updated to use EnsureTools instead of deprecated methods
• cmd/tools.go - Updated display logic for simplified interface
• pkg/config/config.go - Removed deprecated Pre/Post hook fields
• pkg/tools/base_tool.go - Removed deprecated methods and cache interfaces
• pkg/tools/manager.go - Updated Tool interface, removed deprecated methods
• pkg/tools/java.go - Updated signature, removed unused methods, clarified architecture
• pkg/tools/go.go - Updated signature, removed unused methods
• pkg/tools/node.go - Updated signature, removed unused methods
• pkg/tools/maven.go - Updated signature, removed unused getVersionsURL
• pkg/tools/mvnd.go - Updated signature, removed unused getVersionsURL
• pkg/tools/download.go - Updated GetChecksum call, removed fallback logic
• pkg/tools/checksum_test.go - Updated tests for new signature

Testing

• ✅ All unit tests pass
• ✅ All integration tests pass
• ✅ Build passes successfully
• ✅ No functionality broken

Impact

• Massive code reduction: Removed 243+ lines of deprecated/unused code
• Cleaner Tool interface with only necessary public methods
• Better separation of concerns between installation-time and on-demand checksum fetching
• More extensible architecture for future tool implementations
• Improved maintainability by eliminating dead code
• SOLID principles compliance with focused, single-responsibility interfaces
• No breaking changes to existing functionality

Code Quality Improvements

• Eliminated deprecated wrapper methods that were causing confusion
• Removed redundant Name() methods in favor of consistent GetToolName()
• Cleaned up unused cache management interfaces
• Simplified tool metadata handling
• Better encapsulation of internal implementation details
• Improved interface consistency across all tools
• Enhanced documentation of Java's unique checksum architecture

Migration Path

All deprecated methods have been replaced with their modern equivalents:

• InstallTool*() → EnsureTool()/EnsureTools()
• tool.Name() → tool.GetToolName()
• ToolMetadataProvider → Direct tool.GetDisplayName() calls

This cleanup significantly improves code maintainability while preserving all existing functionality.