notify extension dev server of app assets updates

[isaacroldan]

WHY are these changes introduced?

Adds support for serving app-level assets (such as admin static files) through the development server to enable proper asset handling during local development.

WHAT is this pull request doing?

• Adds appAssetsConfig interface to extension specifications to define asset configuration
• Implements appAssetsConfig for admin extensions to handle static_root configuration
• Creates new HTTP middleware to serve app assets at /extensions/assets/:assetKey/ endpoints
• Adds asset metadata to the extensions payload including URLs and timestamps
• Updates file watcher to monitor all real extensions instead of just non-config extensions
• Changes manifest generation to overwrite existing manifest.json files instead of throwing errors
• Includes asset timestamp updates when extension events occur
• Adds workaround to always include admin extension in dev session manifests

How to test your changes?

1. Create an app with an admin extension that has static_root configured
2. Add static assets to the configured directory
3. Run shopify app dev
4. Verify assets are accessible at the generated asset URLs
5. Modify assets and confirm timestamps update properly
6. Test that manifest.json generation works when files already exist

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes
• I've considered analytics changes to measure impact
• The change is user-facing, so I've added a changelog entry with pnpm changeset add

[isaacroldan]

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

• Expose allowed_domains on the app #7240
• notify extension dev server of app assets updates #7227 👈 (View in Graphite)
• Extract custom watch paths to specifications #7220 : 1 other dependent PR (#7226 )
• Use extension handle to identify extensions in file-watcher #7224
• 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/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'>;
 /**