feat: Implement Vim-style line editing mode for enhanced CLI experience

- Added a new `VimMode` class to provide Vim keybindings for terminal interactions, including normal, insert, and visual modes.
- Implemented command history navigation and tab completion features to improve user experience.
- Introduced syntax highlighting for code blocks and various editing commands to enhance functionality.
- Created an enum `VimModeType` to represent different editing modes, facilitating mode management within the CLI.

src/cli/service/agent/vim_mode.h

@@ -0,0 +1,157 @@
+#ifndef YAZE_CLI_SERVICE_AGENT_VIM_MODE_H_
+#define YAZE_CLI_SERVICE_AGENT_VIM_MODE_H_
+
+#include <string>
+#include <vector>
+#include <functional>
+
+namespace yaze {
+namespace cli {
+namespace agent {
+
+/**
+ * @enum VimModeType
+ * @brief Vim editing modes
+ */
+enum class VimModeType {
+  NORMAL,      // Command mode (ESC)
+  INSERT,      // Insert mode (i, a, o, etc.)
+  VISUAL,      // Visual selection mode (v)
+  COMMAND_LINE // Ex command mode (:)
+};
+
+/**
+ * @class VimMode
+ * @brief Vim-style line editing for z3ed CLI chat
+ * 
+ * Provides vim keybindings for enhanced terminal UX:
+ * - Normal mode: hjkl navigation, dd, yy, p, u
+ * - Insert mode: Regular text input
+ * - Command history: Ctrl+P, Ctrl+N or j/k in normal mode
+ * - Tab completion for commands
+ * - Syntax highlighting for code blocks
+ */
+class VimMode {
+ public:
+  VimMode();
+  
+  /**
+   * @brief Process a key press
+   * @param ch Character input
+   * @return True if the line is complete (Enter pressed in insert mode)
+   */
+  bool ProcessKey(int ch);
+  
+  /**
+   * @brief Get the current line being edited
+   */
+  std::string GetLine() const { return current_line_; }
+  
+  /**
+   * @brief Get the current mode
+   */
+  VimModeType GetMode() const { return mode_; }
+  
+  /**
+   * @brief Get mode string for display
+   */
+  std::string GetModeString() const;
+  
+  /**
+   * @brief Get cursor position
+   */
+  int GetCursorPos() const { return cursor_pos_; }
+  
+  /**
+   * @brief Reset for new line
+   */
+  void Reset();
+  
+  /**
+   * @brief Add line to history
+   */
+  void AddToHistory(const std::string& line);
+  
+  /**
+   * @brief Set autocomplete callback
+   */
+  void SetAutoCompleteCallback(std::function<std::vector<std::string>(const std::string&)> callback) {
+    autocomplete_callback_ = callback;
+  }
+  
+  /**
+   * @brief Set command suggestion callback
+   */
+  void SetCommandSuggestionCallback(std::function<std::string(const std::string&)> callback) {
+    command_suggestion_callback_ = callback;
+  }
+  
+  /**
+   * @brief Render the current line with syntax highlighting
+   */
+  void Render() const;
+  
+ private:
+  // Mode handling
+  void SwitchMode(VimModeType new_mode);
+  
+  // Normal mode commands
+  void HandleNormalMode(int ch);
+  void MoveLeft();
+  void MoveRight();
+  void MoveWordForward();
+  void MoveWordBackward();
+  void MoveToLineStart();
+  void MoveToLineEnd();
+  void DeleteChar();
+  void DeleteLine();
+  void YankLine();
+  void PasteBefore();
+  void PasteAfter();
+  void Undo();
+  void Redo();
+  
+  // Insert mode commands
+  void HandleInsertMode(int ch);
+  void InsertChar(char c);
+  void Backspace();
+  void Delete();
+  void Complete();
+  
+  // History navigation
+  void HistoryPrev();
+  void HistoryNext();
+  
+  // Visual feedback
+  void ShowSuggestion() const;
+  
+  VimModeType mode_ = VimModeType::INSERT;
+  std::string current_line_;
+  int cursor_pos_ = 0;
+  
+  // History
+  std::vector<std::string> history_;
+  int history_index_ = -1;
+  
+  // Undo/redo
+  std::vector<std::string> undo_stack_;
+  std::vector<std::string> redo_stack_;
+  
+  // Yank buffer
+  std::string yank_buffer_;
+  
+  // Autocomplete
+  std::function<std::vector<std::string>(const std::string&)> autocomplete_callback_;
+  std::function<std::string(const std::string&)> command_suggestion_callback_;
+  std::vector<std::string> autocomplete_options_;
+  int autocomplete_index_ = 0;
+  
+  // State
+  bool line_complete_ = false;
+};
+
+}  // namespace agent
+}  // namespace cli
+}  // namespace yaze
+
+#endif  // YAZE_CLI_SERVICE_AGENT_VIM_MODE_H_