Fix zsh git branch refresh race after cwd change (#71)

* Fix zsh git branch refresh race after cwd change

* Clarify intentional duplicate cwd check in git refresh path

* Add Metal Toolchain download step to CI and release workflows

Fixes build failure when compiling Metal shaders for iOS xcframework
targets — the self-hosted runner needs `xcodebuild -downloadComponent
MetalToolchain` installed before `xcrun metal` can run.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -55,6 +55,9 @@ jobs:
           xcodebuild -version
           xcrun --sdk macosx --show-sdk-path
 
+      - name: Download Metal Toolchain
+        run: xcodebuild -downloadComponent MetalToolchain
+
       - name: Build GhosttyKit.xcframework
         run: |
           set -euo pipefail

.github/workflows/release.yml

@@ -46,6 +46,9 @@ jobs:
           brew install zig
           npm install --global create-dmg
 
+      - name: Download Metal Toolchain
+        run: xcodebuild -downloadComponent MetalToolchain
+
       - name: Build GhosttyKit.xcframework
         run: |
           cd ghostty