New Diff Rendering Engine

The diff display system has been completely overhauled with several new components:

• Sq2 - Core diff generation using the underlying diff library
• uq2 - Main diff component that renders patches with word-level highlighting
• zV9 - Preprocesses diff lines and identifies line types (add/remove/unchanged)
• QV9 - Matches removed lines with their corresponding additions for word-diff analysis
• qV9 - Performs word-level diff comparison between matched lines
• RV9 - Renders individual lines with word-level highlighting
• UV9 - Orchestrates the complete diff rendering process
• ff - Renders line numbers with proper formatting
• fV9 - Assigns line numbers to diff entries
• od - Feature flag wrapper that enables word-level diff when available