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.

zsh/.zshrc

@@ -103,18 +103,26 @@ fi
 # alias zshconfig="mate ~/.zshrc"
 # alias ohmyzsh="mate ~/.oh-my-zsh"
 
-export PATH="/Users/jsarthak/flutter-sdk/flutter/bin:$PATH"
 
-source <(fzf --zsh)
-
-# Added by Antigravity
-export PATH="/Users/jsarthak/.antigravity/antigravity/bin:$PATH"
-export PATH="/Users/jsarthak/flutter-sdk/flutter/bin:$PATH"
-export PATH="/opt/homebrew/bin:/opt/homebrew/sbin:$PATH"
-source ~/.config/shell/common
-source ~/.config/shell/personal
-source ~/.config/shell/aliases
+# ── Shared shell config ────────────────────────────────────────────────────────────────
+[[ -f ~/.config/shell/common   ]] && source ~/.config/shell/common
+[[ -f ~/.config/shell/personal ]] && source ~/.config/shell/personal
+[[ -f ~/.config/shell/aliases  ]] && source ~/.config/shell/aliases
 
 MANPAGER="col -b | cat"
 MANROFFOPT="-P-c"
 eval "$(zoxide init zsh)"
+
+# ── Strategy 1: Dynamic Runtime Sourcing ─────────────────────────────────────────
+# Detect OS and source the matching platform overlay.
+# macos  → shell/.config/shell/macos  (Homebrew, Flutter, fzf, Antigravity)
+# linux  → shell/.config/shell/linux  (xdg-open, xclip, fzf)
+case "$(uname -s)" in
+  Darwin) [[ -f ~/.config/shell/macos ]] && source ~/.config/shell/macos ;;
+  Linux)  [[ -f ~/.config/shell/linux ]] && source ~/.config/shell/linux ;;
+esac
+
+# ── Per-machine local override (untracked) ──────────────────────────────────
+# Create ~/.zshrc.local on each machine for secrets / profile sourcing.
+# On work machines: export DOTFILES_PROFILE=work && source ~/.config/shell/work
+[[ -f ~/.zshrc.local ]] && source ~/.zshrc.local