feat: Dual-OS Neovim MCP Integration

- Created linux-nvim and win-nvim MCP servers for deep Neovim Msgpack-RPC integration.
- Implemented tools: nvim_goto_line, nvim_get_active_buffer, nvim_get_cursor, nvim_get_visual_selection, nvim_set_diagnostics.
- Added gemini-integration.lua for active UI socket discovery.
- Updated build.cmd to cross-compile for both Windows (gnu) and Linux (musl).
- Updated README, design.md, and instructions.md with architecture and tool capabilities.

win-nvim/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "mcp-memory-win-nvim"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+rmp-serde = "1.1"
+rmpv = "1.0"
+tokio = { version = "1.37", features = ["full"] }
+schemars = "0.8"