fix(tooling): make web fixture setup and dist copying reliable

[OskarEichler]

Fixes

Route stale Expo aliases to the actual web fixture, fix the Android e2e entrypoint, import React Native View, replace the private locked registry URL with the public URL for the identical artifact, and make dist copying cwd-independent, fail-fast and usable once without fswatch. Refuse a destination symlink back to the source.

Compatibility / observable changes

Developer-tooling only. Existing Expo aliases remain available. Copying now fails when required inputs are missing; rsync removes only stale files in the exact installed fixture dist directory. No runtime dependency/version change.

Verification

• Consumer verification: the combined fixes were packaged on the unchanged npm 2.3.2 runtime baseline and checked with React Native 0.87.1 / React 19.2.3. Immutable install, lint, both Android Debug variants, both unsigned iOS Simulator variants, four Metro bundles, 13 web targets and four browser-extension builds pass. All 298 installed non-metadata package files match the reviewed artifact byte-for-byte.
• Independent patch applied to 435b5141df4960ebbbc0b93264db3f5a4b23fffd: all 187 existing tests (14 suites), library TypeScript build and changed-file ESLint pass.
• One-off actual-source regression diagnostics pass:
  • copy works outside repository and removes stale output
  • copy rejects missing build without altering installed package
  • copy rejects a symlink back to its source
• The combined review workspace passes Android Debug, unsigned iOS Simulator Debug/Release, both production Metro bundles, web production export, Docusaurus/Jekyll builds and all 24 existing iOS Detox tests (10 suites). The contacts comparison was rerun after its final change. These combined-workspace results are not a claim that every device/platform was tested independently for this PR.
• No checked-in tests, reference screenshots, dependency versions or native SDK versions were changed.

Reviewers’ hat-rack 🎩

• Check the stated compatibility behavior and reproduce the relevant cases above.
• Run the existing test/type/lint commands and exercise the affected example or list behavior on your supported device matrix.

Physical-device behavior, Android Detox, assistive-technology conformance and release signing were not verified. No app deployment is part of this PR.

[OskarEichler]

I have signed the CLA!