fix: use bufloaded instead of bufexists for file reload check

feat: add quick response feature

fix: check buffer exists before reloading edited files

feat: skill picker

feat: replace welcome buffer with OCPrompt buffer

feat: autoreload edited files

refactor: organize keymaps

quick: update keymap

refactor: remove duplicated get_client() helper from command modules

fix: kill orphaned OpenCode processes on Neovim exit

feat: add OCSessionPick — fuzzy session picker with TUI navigation

feat: add OCSlashCommand picker to list and execute slash commands

feat: update some keymaps

feat: add TUI commands, keymaps, and which-key group labels

feat: replace @ file reference syntax with ./ and change picker trigger to ..