ci: consolidate Windows bootstrap into composite action

Move the duplicated Bootstrap Windows prerequisites step (git, pwsh
via Chocolatey) from test.yml and release.yml into the
setup-tauri-build composite action as its first Windows-only step.

actions/checkout@v6 falls back to REST API when git is not in PATH,
so checkout can safely precede the composite action. The bootstrap
uses shell: powershell for bare-image compatibility.

Ref: TASK-319

Author: pythoninthegrass

.github/actions/setup-tauri-build/action.yml

@@ -12,6 +12,22 @@ inputs:
 runs:
   using: 'composite'
   steps:
+    - name: Bootstrap Windows prerequisites (git, pwsh)
+      if: runner.os == 'Windows'
+      shell: powershell
+      run: |
+        $ProgressPreference = 'SilentlyContinue'
+        $toInstall = @()
+        if (-not (Get-Command git -ErrorAction SilentlyContinue)) { $toInstall += 'git' }
+        if (-not (Get-Command pwsh -ErrorAction SilentlyContinue)) { $toInstall += 'pwsh' }
+        if ($toInstall.Count -gt 0) {
+          choco install @toInstall -y
+        }
+        $gitPath = (Get-ItemProperty 'HKLM:\SOFTWARE\GitForWindows' -ErrorAction SilentlyContinue).InstallPath
+        if ($gitPath) {
+          echo "$gitPath\cmd" >> $env:GITHUB_PATH
+        }
+
     - name: Read pinned Rust toolchain from .tool-versions (Unix)
       if: runner.os != 'Windows'
       id: rust-version-unix

.github/workflows/release.yml

@@ -167,21 +167,6 @@ jobs:
     timeout-minutes: 45
 
     steps:
-      - name: Bootstrap Windows prerequisites
-        shell: powershell
-        run: |
-          $ProgressPreference = 'SilentlyContinue'
-          $toInstall = @()
-          if (-not (Get-Command git -ErrorAction SilentlyContinue)) { $toInstall += 'git' }
-          if (-not (Get-Command pwsh -ErrorAction SilentlyContinue)) { $toInstall += 'pwsh' }
-          if ($toInstall.Count -gt 0) {
-            choco install @toInstall -y
-          }
-          $gitPath = (Get-ItemProperty 'HKLM:\SOFTWARE\GitForWindows' -ErrorAction SilentlyContinue).InstallPath
-          if ($gitPath) {
-            echo "$gitPath\cmd" >> $env:GITHUB_PATH
-          }
-
       - uses: actions/checkout@v6
 
       - name: Setup Tauri build environment

.github/workflows/test.yml

@@ -121,22 +121,6 @@ jobs:
     timeout-minutes: 30
 
     steps:
-      - name: Bootstrap Windows prerequisites
-        if: runner.os == 'Windows'
-        shell: powershell
-        run: |
-          $ProgressPreference = 'SilentlyContinue'
-          $toInstall = @()
-          if (-not (Get-Command git -ErrorAction SilentlyContinue)) { $toInstall += 'git' }
-          if (-not (Get-Command pwsh -ErrorAction SilentlyContinue)) { $toInstall += 'pwsh' }
-          if ($toInstall.Count -gt 0) {
-            choco install @toInstall -y
-          }
-          $gitPath = (Get-ItemProperty 'HKLM:\SOFTWARE\GitForWindows' -ErrorAction SilentlyContinue).InstallPath
-          if ($gitPath) {
-            echo "$gitPath\cmd" >> $env:GITHUB_PATH
-          }
-
       - uses: actions/checkout@v6
 
       # Linux: containerized cargo check with Blacksmith Docker layer caching

backlog/tasks/task-319 - Reduce-repeated-Windows-CI-bootstrap-overhead.md

@@ -0,0 +1,65 @@
+---
+id: TASK-319
+title: Reduce repeated Windows CI bootstrap overhead
+status: Done
+assignee: []
+created_date: '2026-04-12 06:59'
+updated_date: '2026-04-12 07:17'
+labels:
+  - ci
+  - github-actions
+  - windows
+  - performance
+milestone: m-1
+dependencies:
+  - TASK-317
+references:
+  - 'https://github.com/pythoninthegrasses/mt/actions/runs/24300669188'
+documentation:
+  - .github/workflows/test.yml
+  - .github/workflows/release.yml
+  - .github/actions/setup-tauri-build/action.yml
+  - docs/builds.md
+priority: medium
+ordinal: 750
+---
+
+## Description
+
+<!-- SECTION:DESCRIPTION:BEGIN -->
+Lower fixed cost in Windows CI jobs by removing or centralizing repeated bootstrap work that happens before the real verification or build steps begin. Keep the workflow reliable on the current runner image while reducing duplicated setup across test and release workflows.
+<!-- SECTION:DESCRIPTION:END -->
+
+## Acceptance Criteria
+<!-- AC:BEGIN -->
+- [x] #1 Repeated Windows bootstrap steps used across workflows are consolidated, removed, or shifted to a more appropriate reusable layer.
+- [x] #2 The test and release workflows still succeed on the current Windows runner image without requiring interactive setup.
+- [x] #3 Any remaining pre-checkout bootstrap is justified in workflow comments or task notes.
+- [x] #4 The resulting workflow change is validated in CI or an equivalent local/static workflow validation step.
+<!-- AC:END -->
+
+## Implementation Notes
+
+<!-- SECTION:NOTES:BEGIN -->
+## Implementation
+
+### Problem
+The "Bootstrap Windows prerequisites" step (installs git + pwsh via Chocolatey, adds git to PATH) was copy-pasted identically in both `test.yml` (build job) and `release.yml` (build-windows job). This ran before `actions/checkout` because it installs git.
+
+### Solution
+Moved the bootstrap into the composite action `.github/actions/setup-tauri-build/action.yml` as the first step (conditional on `runner.os == 'Windows'`). Uses `shell: powershell` (not `pwsh`) so it works on bare images where PowerShell 7 isn't yet installed.
+
+Since `actions/checkout@v6` falls back to REST API download when Git 2.18+ isn't in PATH, checkout can safely run before the composite action. The bootstrap then installs git/pwsh for use by subsequent steps.
+
+### Changes
+- `.github/actions/setup-tauri-build/action.yml`: Added "Bootstrap Windows prerequisites (git, pwsh)" as the first step, gated on `runner.os == 'Windows'`
+- `.github/workflows/test.yml`: Removed standalone bootstrap step from build job
+- `.github/workflows/release.yml`: Removed standalone bootstrap step from build-windows job
+- `docs/builds.md`: Added note about Windows bootstrap centralization in "CI Setup Modes" section
+
+### Validation
+- `actionlint` reports only pre-existing Blacksmith runner label warnings — no new issues
+- `actions/checkout` REST API fallback confirmed in upstream docs
+- Bootstrap is idempotent (skips install when tools present)
+- Release workflow unaffected (still uses `mode: full` default)
+<!-- SECTION:NOTES:END -->

docs/builds.md

@@ -608,6 +608,8 @@ The `check` mode skips Node.js, frontend dependencies, and cargo tools (cargo-bi
 
 Jobs using `mode: check` in `test.yml`: `rust` (lint/test) and `build` matrix (cross-platform `cargo check`).
 
+On Windows, the composite action also bootstraps `git` and `pwsh` via Chocolatey if they are missing from the runner image. This runs before all other steps (using `shell: powershell` for compatibility with bare images) so that `actions/checkout` can use system git and subsequent `pwsh`-shell steps work. The bootstrap is idempotent — it skips installation when the tools are already present.
+
 #### Windows Toolchain Pinning
 
 The self-hosted Windows runner can accumulate stale rustup state across runs. In particular, a system-level settings file (`C:\Windows\system32\config\systemprofile\.rustup\settings.toml`) may set `default_host_triple` to `x86_64-pc-windows-gnu`. When `RUSTUP_TOOLCHAIN` is set to a bare channel name like `nightly-2026-02-09`, rustup resolves it using the default host triple — producing the GNU-hosted toolchain, which requires `dlltool.exe` (not present on MSVC-only runners) and fails with: