Problem: unused variables (undo_state, sha_result, date match
captures) and duplicate if/else branches in gcal sync triggered
selene warnings and errors.
Solution: prefix unused state with underscore, simplify date
validation to a single pattern match, remove dead sha_result
call, and merge duplicate event deletion branches into a single
condition.
Problem: need user-facing :Todo command, buffer-local keymaps,
Plug mappings, completion toggle, help float, archive, and
syntax highlighting.
Solution: add init.lua with command dispatcher, toggle complete/
priority, date prompt, archive purge, and help float. Add
plugin/todo.lua entry point with :Todo command and Plug mappings.
Add syntax/todo.vim for conceal and priority highlighting.
