fix(create): honor explicit package manager outside monorepos

crates/vite_cli_snapshots/tests/cli_snapshots/fixtures/create_from_nonworkspace_subdir/snapshots.toml

@@ -3,7 +3,8 @@ name = "create_from_nonworkspace_subdir"
 vp = "global"
 skip-platforms = ["windows"]
 steps = [
-  { argv = ["vp", "create", "--no-interactive", "vite:application"], cwd = "scripts", comment = "from non-monorepo subdir", snapshot = false, continue-on-failure = true },
+  { argv = ["vp", "create", "--no-interactive", "--package-manager", "pnpm", "vite:application"], cwd = "scripts", comment = "explicit package manager overrides the non-workspace ancestor", snapshot = false, continue-on-failure = true },
   { argv = ["vpt", "stat-file", "scripts/vite-plus-application/package.json", "--assert", "file"], comment = "created at scripts/vite-plus-application", continue-on-failure = true },
+  { argv = ["vpt", "grep-file", "scripts/vite-plus-application/package.json", "\"name\": \"pnpm\""], comment = "pins pnpm in devEngines", continue-on-failure = true },
   { argv = ["vpt", "stat-file", "vite-plus-application/package.json", "--assert-not", "file"], comment = "not created at parent root", continue-on-failure = true },
 ]

crates/vite_cli_snapshots/tests/cli_snapshots/fixtures/create_from_nonworkspace_subdir/snapshots/create_from_nonworkspace_subdir.md

@@ -1,8 +1,8 @@
 # create_from_nonworkspace_subdir
 
-## `cd scripts && vp create --no-interactive vite:application`
+## `cd scripts && vp create --no-interactive --package-manager pnpm vite:application`
 
-from non-monorepo subdir
+explicit package manager overrides the non-workspace ancestor
 
 
 ## `vpt stat-file scripts/vite-plus-application/package.json --assert file`
@@ -13,6 +13,14 @@ created at scripts/vite-plus-application
 scripts/vite-plus-application/package.json: file
 ```
 
+## `vpt grep-file scripts/vite-plus-application/package.json '"name": "pnpm"'`
+
+pins pnpm in devEngines
+
+```
+scripts/vite-plus-application/package.json: found "\"name\": \"pnpm\""
+```
+
 ## `vpt stat-file vite-plus-application/package.json --assert-not file`
 
 not created at parent root

packages/cli/src/create/bin.ts

@@ -826,7 +826,7 @@ Use \`vp create --list\` to list all available templates, or run \`vp create --h
     }
   }
 
-  // Resolve package manager: workspace detection > CLI flag > interactive prompt/default
+  // Resolve package manager: existing monorepo > CLI flag > ambient detection > prompt/default
   if (
     options.packageManager &&
     !Object.values(PackageManager).includes(options.packageManager as PackageManager)
@@ -837,16 +837,23 @@ Use \`vp create --list\` to list all available templates, or run \`vp create --h
     );
     cancelAndExit('Invalid --package-manager value', 1);
   }
+  const requestedPackageManager = options.packageManager as PackageManager | undefined;
+  const detectedPackageManager = workspaceInfoOptional.packageManager;
   const packageManager =
-    workspaceInfoOptional.packageManager ??
-    (options.packageManager as PackageManager | undefined) ??
+    (isMonorepo
+      ? (detectedPackageManager ?? requestedPackageManager)
+      : (requestedPackageManager ?? detectedPackageManager)) ??
     (await selectPackageManager(options.interactive, compactOutput));
+  const packageManagerVersion =
+    packageManager === detectedPackageManager
+      ? workspaceInfoOptional.packageManagerVersion
+      : 'latest';
   const shouldSilencePackageManagerInstallLog =
     compactOutput || (isMonorepo && workspaceInfoOptional.packageManager !== undefined);
   // ensure the package manager is installed by vite-plus
   const downloadResult = await downloadPackageManager(
     packageManager,
-    workspaceInfoOptional.packageManagerVersion,
+    packageManagerVersion,
     options.interactive,
     shouldSilencePackageManagerInstallLog,
   );

rfcs/package-manager-detection.md

@@ -145,11 +145,12 @@ vp create vite:monorepo --no-interactive --package-manager bun
 
 **Resolution priority for `vp create`**:
 
-1. Detected workspace package manager (`packageManager` field or `devEngines.packageManager`; existing monorepo takes precedence)
+1. Any package manager detected for an existing monorepo (from manifest fields, workspace files, lockfiles, or package-manager configuration)
 2. `--package-manager` CLI flag
-3. Interactive prompt / auto-default (pnpm)
+3. Package manager detected from a non-monorepo ancestor
+4. Interactive prompt / auto-default (pnpm)
 
-This ensures monorepo consistency: if you run `vp create` inside an existing workspace that already has a `packageManager` field, the workspace setting wins over the CLI flag.
+This ensures monorepo consistency while allowing standalone projects to override ambient detection explicitly.
 
 ## Auto-Update Behavior