enable persistant undo history

LOG.md

@@ -83,6 +83,7 @@ Record every decision here with a short rationale. Append new entries; do not re
   - **Templates**: Shell script template (template.sh) auto-loaded via BufNewFile autocmd for `*.sh` files
   - **Whitespace highlighting**: Already handled via `listchars` in Phase 3.2 (settings.lua)
   - **Persistent folds**: Not needed; UFO handles folding without explicit persistence mechanism
+  - **Persistent undo**: Re-enabled 2025-01-06 via `undofile=true` and `undodir` in settings.lua (preserves undo history across sessions)
 - 2025-12-11: Colorscheme Phase 11.2:
   - **Color palette extraction**: Extracted all 45 color definitions from original Paper Tonic colorscheme
   - **Structure**: Created `lua/paper-tonic-modern/colors.lua` with comprehensive documentation

MIGRATION_PLAN.md

@@ -24,6 +24,7 @@ Source of truth for the step-by-step rebuild. Keep this concise and up to date.
 
 ## Phase 1.6 — Preserve selected directories
 - [x] Keep `undodir`, `spell`, `view`, `UltiSnips`, `templates` as-is for now (review later)
+- [x] Re-enabled persistent undo in settings.lua (2025-01-06)
 
 ## Phase 2 — Bootstrap
 

lua/settings.lua

@@ -49,6 +49,10 @@ vim.opt.shiftwidth = 4 -- Indent by 4
 vim.opt.softtabstop = 4 -- Backspace removes 4 spaces
 vim.opt.expandtab = true -- Use spaces by default (overridden per-filetype)
 
+-- Persistent undo
+vim.opt.undofile = true -- Enable persistent undo
+vim.opt.undodir = vim.fn.stdpath("config") .. "/undodir" -- Store undo files in config directory
+
 -- LSP diagnostics configuration
 vim.diagnostic.config({
 	virtual_text = {