Update CLAUDE.md - Feature Class Structure and Main Class Explanations

[xterao]

This pull request updates the CLAUDE.md documentation to provide clearer, more structured explanations of the main classes and architecture for each major plugin feature.

The changes include:
Separation of Plugin Overview and Feature Details: The document now clearly distinguishes between the overall plugin architecture and the detailed explanations of each feature.

New Section:
"Main Classes of Each Feature": Added a dedicated section that describes the main classes for each feature (Actions, Inspections, Refactoring, Reference Resolution, Documentation, Formatter, etc.), with consistent heading levels and categorization.

Detailed Class Descriptions:
For each feature, the main classes are listed with concise explanations of their roles and processing targets. For example, the Refactoring section now distinguishes between processors for DAO class renaming, DAO method renaming, and package renaming.

Class Naming Conventions:
Each feature section now explicitly states the naming conventions for its main classes (e.g., suffixes like Processor, Reference, DocumentationProvider, etc.).

Reduced Heading Nesting:
The document structure has been flattened for better readability, with all feature details grouped under a single "Main Classes of Each Feature" section.