docs: Remove outdated code optimization plan document

PLAN.md

@@ -1,63 +0,0 @@
-# Code Optimization Plan - Status Update
-
-This document outlines optimizations to reduce boilerplate code and improve maintainability through the use of derive macros and utility crates.
-
-## ✅ 1. Add Utility Crates to Cargo.toml - COMPLETED
-
-**Files affected:**
-- `Cargo.toml` - `thiserror` and `derive_more` are already present
-
-## ✅ 2. Replace Manual Debug Implementations with Derives - MOSTLY COMPLETED
-
-**Files affected:**
-- Most structs now use `#[derive(Debug)]` instead of manual implementations
-- Remaining manual implementations appear intentional for specific formatting
-
-## ✅ 3. Replace Manual Default Implementations with Derives - PARTIALLY COMPLETED
-
-**Files affected:**
-- Many plugins use `#[derive(Default)]` or `#[derive(SmartDefault)]`
-- Some still have manual implementations that could potentially be simplified
-
-## ✅ 4. Use thiserror for Error Types - PARTIALLY COMPLETED
-
-**Files affected:**
-- `src/services/error.rs` - CoreError enum uses thiserror ✅
-- `src/modes/server/mcp/tools.rs` - ToolError enum could be updated
-
-## 🔄 5. Use derive_more for Common Trait Implementations - PENDING
-
-**Files affected:**
-- Wrapper types throughout the codebase could benefit from derive_more
-- This would further reduce boilerplate code
-
-## ✅ 6. Enhance Serde Usage - MOSTLY COMPLETED
-
-**Files affected:**
-- Most response and configuration types use `#[derive(Serialize, Deserialize)]`
-- Field naming appears consistent
-
-## ✅ 7. Improve Strum Usage for Enums - COMPLETED
-
-**Files affected:**
-- `src/compression_engine.rs` - CompressionType uses strum ✅
-- `src/meta_plugin/mod.rs` - MetaPluginType uses strum ✅
-
-## 🔄 8. Code Organization Improvements - ONGOING
-
-**Files affected:**
-- All source files could benefit from consistent derive ordering and import organization
-
-## Implementation Status
-
-1. **✅ High Priority**: Crates are already in Cargo.toml
-2. **✅ Medium Priority**: Error handling mostly uses thiserror
-3. **✅ Medium Priority**: Debug and Default derives mostly implemented
-4. **🔄 Low Priority**: derive_more usage could be expanded
-
-## Remaining Opportunities
-
-- Apply `#[derive(thiserror::Error)]` to `ToolError` in `src/modes/server/mcp/tools.rs`
-- Use `derive_more` for wrapper types to reduce boilerplate
-- Ensure consistent import ordering across all files
-- Standardize derive attribute ordering