Add root-known package manager helper

[dmerand]

What

This follow-up is part of the same package-manager stack as #7239.

Add a helper for callers that already know the project root, and use it for project metadata and root dependency update paths instead of routing back through npm prefix.

Why

This stack is not about reducing Shopify CLI's supported package managers.

The problem is that different callers need different package-manager resolution modes. #7239 handles directory-local execution for function typegen. This PR handles callers that already know the project root.

The end state is for callers to choose intent, not implementation.

How

Add getPackageManagerForProjectRoot(...) to inspect a known project root directly.

Use it from:

• Project.load(...)
• addResolutionOrOverride(...)
• local upgrade dependency updates

Also narrow Project.packageManager to project-valid values plus 'unknown' when the app root has no package.json.

[dmerand]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Use Project follow-up command helper for display-only paths #7243
• Require explicit package manager for project operations #7242
• Add root-known package manager helper #7241 👈 (View in Graphite)
• Use function directory package manager for GraphQL typegen #7239
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[github-actions]

Differences in type declarations

We detected differences in the type declarations generated by Typescript for this branch compared to the baseline ('main' branch). Please, review them to ensure they are backward-compatible. Here are some important things to keep in mind:

• Some seemingly private modules might be re-exported through public modules.
• If the branch is behind main you might see odd diffs, rebase main into this branch.

New type declarations

We found no new type declarations in this PR

Existing type declarations

packages/cli-kit/dist/private/node/ui.d.ts

 import { Logger, LogLevel } from '../../public/node/output.js';
-import React from 'react';
 import { Key, RenderOptions } from 'ink';
 import { EventEmitter } from 'events';
-/**
- * Signal that the current Ink tree is done. Must be called within an
- * InkLifecycleRoot — throws if the provider is missing so lifecycle
- * bugs surface immediately instead of silently hanging.
- */
-export declare function useComplete(): (error?: Error) => void;
-/**
- * Root wrapper for Ink trees. Owns the single `exit()` call site — children
- * signal completion via `useComplete()`, which sets state here. The `useEffect`
- * fires post-render, guaranteeing all batched state updates have been flushed
- * before the tree is torn down.
- */
-export declare function InkLifecycleRoot({ children }: {
-    children: React.ReactNode;
-}): React.JSX.Element;
 interface RenderOnceOptions {
     logLevel?: LogLevel;
     logger?: Logger;
     renderOptions?: RenderOptions;
 }
 export declare function renderOnce(element: JSX.Element, { logLevel, renderOptions }: RenderOnceOptions): string | undefined;
-export declare function render(element: JSX.Element, options?: RenderOptions): Promise<void>;
+export declare function render(element: JSX.Element, options?: RenderOptions): Promise<unknown>;
 export declare class Stdout extends EventEmitter {
     columns: number;
     rows: number;
     readonly frames: string[];
     private _lastFrame?;
     constructor(options: {
         columns?: number;
         rows?: number;
     });
     write: (frame: string) => void;
     lastFrame: () => string | undefined;
 }
 export declare function handleCtrlC(input: string, key: Key, exit?: () => void): void;
 export {};

packages/cli-kit/dist/public/node/node-package-manager.d.ts

@@ -27,6 +27,7 @@ export type DependencyType = 'dev' | 'prod' | 'peer';
  */
 export declare const packageManager: readonly ["yarn", "npm", "pnpm", "bun", "homebrew", "unknown"];
 export type PackageManager = (typeof packageManager)[number];
+export type ProjectPackageManager = Extract<PackageManager, 'yarn' | 'npm' | 'pnpm' | 'bun'>;
 /**
  * Returns an abort error that's thrown when the package manager can't be determined.
  * @returns An abort error.
@@ -59,11 +60,68 @@ export declare class FindUpAndReadPackageJsonNotFoundError extends BugError {
  */
 export declare function packageManagerFromUserAgent(env?: NodeJS.ProcessEnv): PackageManager;
 /**
- * Returns the dependency manager used in a directory.
- * @param fromDirectory - The starting directory
- * @returns The dependency manager
+ * Returns the dependency manager governing the project or workspace root discovered from a
+ * starting directory.
+ *
+ * Use this when the caller does not already know the project root and wants the historical
+ * root-finding behavior based on /home/runner/work/cli/cli.
+ *
+ * @param fromDirectory - The starting directory.
+ * @returns The detected package manager, or a user-agent fallback if the root can't be resolved.
  */
 export declare function getPackageManager(fromDirectory: string): Promise<PackageManager>;
+/**
+ * Resolves the package manager for a directory already known to be the project root.
+ *
+ * Use this when the caller already knows the root directory and wants to inspect that root
+ * directly rather than rediscovering it via /home/runner/work/cli/cli.
+ *
+ * @param rootDirectory - The known project root directory.
+ * @returns The package manager detected from root markers, defaulting to npm <command>
+
+Usage:
+
+npm install        install all the dependencies in your project
+npm install <foo>  add the <foo> dependency to your project
+npm test           run this project's tests
+npm run <foo>      run the script named <foo>
+npm <command> -h   quick help on <command>
+npm -l             display usage info for all commands
+npm help <term>    search for help on <term>
+npm help npm       more involved overview
+
+All commands:
+
+    access, adduser, audit, bugs, cache, ci, completion,
+    config, dedupe, deprecate, diff, dist-tag, docs, doctor,
+    edit, exec, explain, explore, find-dupes, fund, get, help,
+    help-search, init, install, install-ci-test, install-test,
+    link, ll, login, logout, ls, org, outdated, owner, pack,
+    ping, pkg, prefix, profile, prune, publish, query, rebuild,
+    repo, restart, root, run-script, sbom, search, set,
+    shrinkwrap, star, stars, start, stop, team, test, token,
+    undeprecate, uninstall, unpublish, unstar, update, version,
+    view, whoami
+
+Specify configs in the ini-formatted file:
+    /home/runner/work/_temp/.npmrc
+or on the command line via: npm <command> --key=value
+
+More configuration info: npm help config
+Configuration fields: npm help 7 config
+
+npm@11.3.0 /opt/hostedtoolcache/node/24.1.0/x64/lib/node_modules/npm when no marker exists.
+ * @throws PackageJsonNotFoundError if the provided directory does not contain a package.json.
+ */
+export declare function getPackageManagerForProjectRoot(rootDirectory: string): Promise<ProjectPackageManager>;
+/**
+ * Builds the command and argv needed to execute a local binary using the package manager
+ * detected from the provided directory or its ancestors.
+ */
+export declare function packageManagerBinaryCommandForDirectory(fromDirectory: string, binary: string, ...binaryArgs: string[]): Promise<{
+    command: string;
+    args: string[];
+}>;
 interface InstallNPMDependenciesRecursivelyOptions {
     /**
      * The dependency manager to use to install the dependencies.

packages/cli-kit/dist/public/node/ui.d.ts

@@ -34,7 +34,7 @@ export interface RenderConcurrentOptions extends PartialBy<ConcurrentOutputProps
  * 00:00:00 │ frontend │ third frontend message
  *
  */
-export declare function renderConcurrent({ renderOptions, ...props }: RenderConcurrentOptions): Promise<void>;
+export declare function renderConcurrent({ renderOptions, ...props }: RenderConcurrentOptions): Promise<unknown>;
 export type AlertCustomSection = CustomSection;
 export type RenderAlertOptions = Omit<AlertOptions, 'type'>;
 /**