refactor: consolidate all branches into single-branch Strategy 1

- bash/.bashrc: replace oh-my-bash with minimal unified config
  sources common → aliases → OS overlay → .bashrc.local

- zsh/.zshrc: remove hardcoded macOS PATHs (moved to macos overlay)
  clean sourcing order: common → personal → aliases → OS → .zshrc.local

- shell/common: populated with universal exports (EDITOR, HISTSIZE, etc.)
- shell/macos: Homebrew, Antigravity, Flutter PATH, fzf init, macOS aliases
- shell/linux: xdg-open, xclip, fzf init for Linux

- nvim/plugins/work.lua: Copilot plugin (migrated from origin/work branch)
- nvim/plugins/_init.lua: conditional load via DOTFILES_PROFILE=work env var

- tmux/.tmux.conf.local: per-machine override hook (~/.tmux.conf.machine.local)

- bootstrap.sh: one-command new machine setup with profile support
  usage: bash bootstrap.sh [personal|work]

- .gitignore: comprehensive .local file ignore patterns

All branches (linux, mac, work, linux_personal, linux_work, mac_personal)
can now be deleted — all unique content is merged into master.

nvim/.config/nvim/lua/kickstart/plugins/_init.lua

@@ -75,7 +75,11 @@ require("lazy").setup({
         "junegunn/seoul256.vim"
 	},
 
-	-- NOTE: Plugins can also be added by using a table,
+	-- ── Work-profile plugins (Copilot) ──────────────────────────────────────
+	-- Loaded only when DOTFILES_PROFILE=work is set (via ~/.zshrc.local).
+	-- On work machines add: export DOTFILES_PROFILE=work
+	(os.getenv("DOTFILES_PROFILE") == "work" and require("kickstart.plugins.work") or {}),
+
 	-- with the first argument being the link and the following
 	-- keys can be used to configure plugin behavior/loading/etc.
 	--

nvim/.config/nvim/lua/kickstart/plugins/work.lua

@@ -0,0 +1,8 @@
+-- Work-machine plugins (Copilot + CopilotChat)
+-- Loaded only when DOTFILES_PROFILE=work is set in the environment.
+-- Add this to your ~/.zshrc.local on work machines:
+--   export DOTFILES_PROFILE=work
+return {
+    "github/copilot.vim",
+    require("kickstart.plugins.copilot_chat"),
+}