Bootstrap-BareRepo.ps1 for fresh-clone onboarding (#420)

.github/skills/polyphony-bootstrap/SKILL.md

@@ -62,7 +62,11 @@ Pick **one real work item ID** to smoke-test against — list with
 
 Follow `docs/onboarding-guide.md` sections 3–9 to:
 
-- Verify (or migrate to) the bare-repo + per-run worktree layout (§ 2)
+- Verify (or create) the bare-repo + per-run worktree layout (§ 2)
+  - **Fresh clone** (no existing local clone): run
+    `~/.polyphony/bin/Bootstrap-BareRepo.ps1 -RemoteUrl <url> [-ParentDir <dir>] [-Commit]`
+    to produce the canonical `<parent>/<repo>.git/ + <parent>/<repo>/ + <parent>/<repo>-runs/` layout.
+  - **Existing operator clone**: run `Migrate-ToBareRepo.ps1` instead.
 - Select your process template (Basic / Agile / Scrum / CMMI / custom)
 - Run `bootstrap-conductor.ps1 -ProcessTemplate <template>` to scaffold
   `.polyphony-config/`

docs/onboarding-guide.md

@@ -144,6 +144,27 @@ git -C ~/projects/<repo> status   # → clean, on main
 
 The script is idempotent, dry-run by default, and never touches `~/projects/<repo>/` until you've explicitly moved it aside in step 1's printed instructions. See [`docs/per-run-worktree-layout.md`](per-run-worktree-layout.md) for the manual procedure if you need to migrate without the script.
 
+### Fresh clone (no existing local checkout)
+
+If you don't have the repo locally yet, use `Bootstrap-BareRepo.ps1` instead — it goes straight to the canonical bare-repo + worktree layout without any migration plumbing:
+
+```powershell
+# Dry-run (default): prints the plan, creates nothing.
+~/.polyphony/bin/Bootstrap-BareRepo.ps1 -RemoteUrl https://github.com/Org/<repo>.git
+
+# Execute:
+~/.polyphony/bin/Bootstrap-BareRepo.ps1 -RemoteUrl https://github.com/Org/<repo>.git -Commit
+
+# Optional overrides:
+#   -ParentDir D:\repos          (default: ~/projects)
+#   -RepoName custom-name        (default: derived from URL)
+#   -MainBranch develop          (default: remote's HEAD branch)
+```
+
+`Bootstrap-BareRepo.ps1` is idempotent: re-running on an existing canonical layout is a no-op. Partial-state recovery (bare present + main worktree missing) is supported as long as the bare's `origin` URL matches the `-RemoteUrl` you pass — identity mismatches refuse rather than overwrite.
+
+On Windows the script always probes via `git --git-dir=<bare>` so it works under `git config --global safe.bareRepository explicit`.
+
 ### Verifying the layout
 
 Two preflight probes confirm the layout is wired correctly:

install.ps1

@@ -108,7 +108,7 @@ Remove-Item $tempSha -Force
 # After that ships, switch $launcherBase to "$base".
 $launcherBase = 'https://raw.githubusercontent.com/PolyphonyRequiem/polyphony/main/scripts'
 Write-Host "==> downloading launcher scripts..." -ForegroundColor Cyan
-foreach ($name in 'Invoke-PolyphonySdlc.ps1', 'Resolve-GhIdentity.ps1', 'Twig-Hydration.ps1', 'Migrate-ToBareRepo.ps1', 'bootstrap-conductor.ps1') {
+foreach ($name in 'Invoke-PolyphonySdlc.ps1', 'Resolve-GhIdentity.ps1', 'Twig-Hydration.ps1', 'Migrate-ToBareRepo.ps1', 'Bootstrap-BareRepo.ps1', 'bootstrap-conductor.ps1') {
     $dest = Join-Path $installDir $name
     Invoke-WebRequest -Uri "$launcherBase/$name" -OutFile $dest
     Unblock-File -Path $dest
@@ -122,6 +122,7 @@ $expectedLaunchers = @(
     'Resolve-GhIdentity.ps1',
     'Twig-Hydration.ps1',
     'Migrate-ToBareRepo.ps1',
+    'Bootstrap-BareRepo.ps1',
     'bootstrap-conductor.ps1'
 )
 $missingLaunchers = @()