Neovim migration — Phase 2: Remove Vim-only quirks

[mattmenefee]

Blocked by

• Neovim migration — Phase 1: Minimum cutover from MacVim #67

---

Small, opportunistic cleanup of options/plugins that are deprecated or redundant under Neovim. Mechanical changes, low risk.

Depends on: Phase 1 (cutover must be complete).

Changes

• Remove set pastetoggle=<F2> — deprecated in Neovim; bracketed-paste handles this automatically. Done in Neovim migration — Phase 1: Minimum cutover from MacVim #67 — option is now a hard error in Neovim 0.12.
• Remove set nocompatible — Neovim is always non-compatible; the option is a no-op.
• Remove Plugin 'matchit.zip' — Neovim ships and auto-loads matchit.
• Audit :checkhealth output and address anything our config triggers.

Acceptance

• nvim --headless +qall produces no deprecation warnings related to our config
• :checkhealth shows no warnings caused by our init.vim