feat(plugin-frustration-browser): stub in frustration browser plugin

[daniel-graham-amplitude]

Summary

• Stub in the frustration plugin
• Made fixes to "plugin-stub-browser" and "plugin-web-vitals-browser" too

Checklist

• Does your PR title have the correct title format?
• Does your PR have a breaking change?: Yes

[promptless]

✅ No documentation updates required.

[Copilot]

Pull Request Overview

Stubs in a new “frustration” browser plugin package and updates related plugins.

• Added a test HTML page and scaffold for the frustration-plugin package (configs, src, tests, docs).
• Removed unused rxjs deps and a publish script from existing browser plugins.
• Updated stub-browser docs & status to alpha.

Reviewed Changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
test-server/autocapture/frustration.html	Add sample HTML page for testing the frustration plugin
packages/plugin-web-vitals-browser/package.json	Remove unused rxjs dependency
packages/plugin-stub-browser/package.json	Remove publish script and rxjs dependency
packages/plugin-stub-browser/README.md	Change plugin status to alpha
packages/plugin-frustration-browser/**/*	Introduce new frustration plugin package scaffold (configs, source, tests, docs)

Comments suppressed due to low confidence (3)

packages/plugin-frustration-browser/test/index.test.ts:7

• Consider adding a test for the execute method to verify it returns the input event (e.g., expect(await plugin.execute(event)).toBe(event)).

it('should call setup and teardown without errors', async () => {

packages/plugin-frustration-browser/jest.config.js:2

• [nitpick] Using package as a variable name can be confusing and may shadow reserved words; consider renaming to pkg or packageJson.

const package = require('./package');

packages/plugin-web-vitals-browser/package.json:42

• Ensure no RxJS imports remain in this package before removing its dependency, otherwise it will break at runtime.

-    "rxjs": "^7.8.1",

[Copilot]

The README header still says (beta) but the package is published under the alpha tag. Update to (alpha) to match publishConfig.tag.

[Copilot]

The install command references @beta but the package is tagged alpha. Change to @alpha to align with the published version.