Task: Add Windows + Git Bash bootstrap support (additive, reuse existing zsh structure)

Hard constraints

• Do not change existing macOS/Linux behavior
• Do not refactor .zshrc, env.zsh, or existing run_onchange_* scripts
• Only add Windows support in a way that plugs into the current structure

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Current shell layout (assume this is correct)

• .zshrc = minimal loader
• env.zsh = bulk of config
• Additional run_onchange_* scripts exist and should remain intact

Windows work should reuse this setup, not duplicate it.

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Goals

1. On Windows, use winget to install common apps + Windows-specific tools.

2. Ensure Git Bash launches into zsh automatically.

3. Ensure your existing zsh flow loads the same way:

   • .zshrc loads env.zsh
   • existing run_onchange_* scripts still run as designed

4. Add minimal Windows conditionals only where necessary (paths, tool availability).

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New manifests (Windows only)

Add:

manifests/windows/common.txt
manifests/windows/windows-only.txt
# optional per-machine:
manifests/windows/{{ .chezmoi.hostname }}.txt

These files contain winget package IDs, one per line, comments allowed.

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New chezmoi script (Windows-only)

Add:

run_onchange_install-windows.ps1.tmpl

Behavior:

• Run only when {{ if eq .chezmoi.os "windows" }}

• Read + merge these lists if present:

  • manifests/windows/common.txt
  • manifests/windows/windows-only.txt
  • manifests/windows/{{ .chezmoi.hostname }}.txt

• For each ID, run:

  • winget install --id <ID> --exact --silent --accept-package-agreements --accept-source-agreements

• Must be idempotent: don’t fail if already installed.

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Git Bash → zsh handoff (Windows)

Add a Git Bash config snippet (via chezmoi-managed file) that:

• Installs zsh in Git Bash using pacman if missing:

  • pacman -S --noconfirm zsh

• Auto-launches zsh when opening Git Bash interactively by adding to ~/.bashrc:

  if [ -t 1 ] && command -v zsh >/dev/null; then
    exec zsh
  fi

• Do not alter .zshrc logic beyond what’s strictly necessary.

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Windows-specific environment handling (minimal)

Add only if needed:

• A small conditional in env.zsh (or a separate env.windows.zsh sourced by env.zsh) to handle:

  • path differences in Git Bash (/c/Users/...)
  • optional tools not present on Windows

• Prefer a separate file (e.g. env.windows.zsh) that env.zsh sources when running on Windows/MSYS to avoid touching existing logic.

Detection suggestion (Git Bash / MSYS):

• $OSTYPE contains msys or cygwin, or uname contains MINGW

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Non-goals

• No WSL setup
• No changes to macOS/Linux install scripts
• No replacement of your existing env/zsh structure
• No deep PowerShell profile customization

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Acceptance criteria

• chezmoi apply on Windows:

  • Installs packages via winget
  • Git Bash opens and immediately runs zsh
  • .zshrc loads env.zsh as it does on macOS/Linux
  • Existing on_change scripts still behave normally

• chezmoi apply on macOS/Linux produces no changes beyond any existing behavior (i.e., no regressions)

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Tiny extra suggestion (optional but smart):
Have the Windows winget script and the Git Bash zsh install be separate run_onchange_ scripts so you can debug them independently.