feat: Complete TextBasedConverter with 40+ algorithms and cleanup

[vuon9]

Summary

This PR completes the TextBasedConverter unified tool and removes all deprecated standalone tools.

🚀 Major Features

Backend - 40+ Algorithms Implemented

• Encryption (8): AES, AES-GCM, DES, Triple DES, ChaCha20, Salsa20, XOR, RC4
• Encoding (12): Base64, Base32, Base58, Base16 (Hex), URL, HTML Entities, Binary, Morse Code, ROT13, ROT47, Quoted-Printable
• Hashing (19): MD5, SHA-1/224/256/384/512, SHA-3, BLAKE2b, BLAKE3, RIPEMD-160, bcrypt, scrypt, Argon2, HMAC, CRC32, Adler-32, MurmurHash3, xxHash, FNV-1a
• Conversion (11): JSON↔YAML, JSON↔XML, JSON↔CSV, YAML↔TOML, Markdown↔HTML, CSV↔TSV, Properties↔JSON, INI↔JSON, Key-Value↔Query String

Frontend - Enhanced UX

• All Hashes View: Grid display showing all 19 hash algorithms at once with individual copy buttons
• Smart Configuration: Auto-shows key/IV inputs only when needed
• Auto-run Mode: Results update instantly as you type (toggleable)
• Layout Toggle: Switch between horizontal/vertical split panes
• Fixed Fast Refresh: Separated constants from components

🧹 Cleanup

• Removed 5 Deprecated Tools:
  • Base64Converter
  • HashGenerator
  • HexAsciiConverter
  • HtmlEntityConverter
  • DataConverter
• Updated Routes: App.jsx and Sidebar.jsx cleaned up
• Documentation: README.md rewritten for end-users, TOOL_STATUS.md updated

🧪 Testing

• 56 Unit Tests: All algorithms covered with table-driven tests
• CI/CD: New GitHub Actions workflow for Go tests
• Build Verification: Tests run on all platforms (Linux, Windows, macOS)

📊 Stats

• +2,673 lines added
• -1,175 lines removed
• 30 files changed
• 5 files deleted (deprecated tools)

Testing

• All Go tests pass: "go test ./internal/converter/... -v"
• Backend builds successfully
• Frontend compiles without errors
• TextBasedConverter works in browser

Checklist

• Implements all listed algorithms in CONVERTER_MAP
• Follows Carbon Design System guidelines
• Uses useReducer for state management
• Copy buttons present on all outputs
• Monospace fonts for data
• No unused imports or variables
• Documentation updated

Ready for review! 🎉