docs(cortex-gui): comprehensive performance & feature roadmap comparing Zed and VSCode

Based on deep analysis of Zed (217 crates) and VSCode (93+ contributions):

Performance Critical (P0):
- Rope data structure for large files (O(log n) operations)
- Enhanced VirtualList with view pooling/recycling
- Sum Tree for efficient position calculations

AI & Intelligence (P1):
- Edit predictions (Zed's killer AI feature)
- True multi-buffer editing with direct sync
- Async LSP with streaming & cancellation

Visual & UX (P2):
- GPU-accelerated minimap rendering
- Real-time collaboration with CRDT
- Incremental syntax highlighting
- Test coverage inline display

Workflow (P3):
- Problem matchers for tasks
- Visual keybinding editor
- Performance profiler integration
- Workspace trust completion

Includes detailed implementation specs, TypeScript interfaces,
and 16-week phased timeline for full implementation.

Author: factorydroid