fix: No longer display tags on stderr data in component testing

[cacieprins]

• Closes webpack info logs less readable with CYPRESS.STDERR annotations - re-open #32569 #32769

Additional details

When Cypress intentionally writes to stderr, it tags the content so that it will be preserved and written to the top level stderr. The @packages/stderr-filtering package takes care of tagging data and filtering the tags (and untagged data) from the stderr stream. This prevents benign stderr messages from Electron from surfacing.

In component testing run mode with webpack 5, the out stream was getting tagged. Unfortunately, that entrypoint to the binary was not captured by the filtering part of @packages/stderr-filtering.

This moves filter streaming from @packages/electron to the spawn logic in @packages/cli, ensuring it wraps the outermost process and filters any tags that come through stderr.

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Note

Medium Risk
Changes the CLI’s child-process stderr piping and introduces packaging-time dependency filtering, which could affect runtime logging/diagnostics and CLI bundling if misconfigured. Also adjusts system-test dependency resolution and fixtures, which may impact CI install behavior for test projects.

Overview
Prevents internal stderr tagging noise from leaking into user-facing CLI output by routing spawned Cypress process stderr through @packages/stderr-filtering in cli/lib/exec/spawn.ts (with pass-through behavior in dev/debug/logging modes).

Updates CLI packaging to include @packages/stderr-filtering for bundling while stripping all @packages/* entries from the published cli/build/package.json.

System tests now reference cypress from cli/build and the dep-installer resolves file: workspace deps to absolute paths relative to the project, with lockfiles updated accordingly.

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Steps to test

1. yarn binary-build (choose: overwrite)
2. yarn binary-package [--skipSigning, if on osx]
3. With the fresh binary, run component testing in the webpack5/react project in cypress-component-testing-apps: https://github.com/cypress-io/cypress-component-testing-apps/tree/main/react-webpack5-js
4. Confirm there is no CYPRESS.STDERR tags in the output stream

How has the user experience changed?

PR Tasks

• Have tests been added/updated?
• [NA] Has a PR for user-facing changes been opened in cypress-documentation?
• [NA] Have API changes been updated in the type definitions?

[cypress]

cypress    Run #69199

Run Properties:   Passed #69199  •  0f5aa8f223: Merge branch 'develop' into fix/ct-stderr-tags-in-prod

Project	cypress
Branch Review	fix/ct-stderr-tags-in-prod
Run status	Passed #69199
Run duration	18m 57s
Commit	0f5aa8f223: Merge branch 'develop' into fix/ct-stderr-tags-in-prod
Committer	Cacie Prins
View all properties for this run ↗︎

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Test results
Failures	0
Flaky	12
Pending	1112
Skipped	0
Passing	27188
View all changes introduced in this branch ↗︎

UI Coverage  61.04%
Untested elements	28
Tested elements	47

Accessibility  99.03%
Failed rules	0 critical   3 serious   1 moderate   0 minor
Failed elements	18

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

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[mschile]

Added a comment.

[alexsch01]

I don't know if this fixes the case with e2e testing as well
if that's true, should the title be changed?