chore(headless,bueno): externalize all packages on node outputs

[louis-bompart]

A couple of changes to allow source maps to work properly for our users, and avoid package duplications in bundles:

• Externalize all dependencies for NPM output
  Stop bundling on NPM. This was an error, causing duplication of heavy libraries such as Redux on customer websites, reducing their overall performance.

• Merge back conditional exports: we don't need those anymore since the bundling we do not pre-bundle anymore

• Create a new CDN output that keeps on bundling: Used for our static.cloud.coveo.com shenanigans

• Update exponential-backoff (some source map fixes)

• Internalize fetch-event sources with its patch (DXUI ownership for the time being): The lib is unmaintained, and its source maps cause issues; the simpler solution is to absorb it.

  • @ThibautNazare: We discussed this point. To ease the transition, we'll take temporary custody of this piece of code until @coveo/service-core can pick it up.
  • @mmitiche, you worked on the patch about the abort controller, I did include it, but I'd like to know if you have some tips & tricks to validate that all's working A-OK :)

• Stencil sample required stabilization due to its known deficiencies with modern module resolution.

  • Sadly, we cant change module resolve conditions programmatically yet in a given node process, thus the horrible spawnSync hack.
  • Even the hack cannot handle/overwrite/discard node, so special resolution for this one --> require NodeJS 22.14.0 for module.findPackageJSON

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fixes #4883

[github-actions]

Pull Request Report

PR Title

✅ Title follows the conventional commit spec.

Live demo links

• Storybook

• Playwright report

Bundle Size

File	Old (kb)	New (kb)	Change (%)
case-assist	244.2	243.7	-0.2
commerce	355.5	355	-0.1
search	415.5	415	-0.1
insight	406.7	406.2	-0.1
recommendation	256.3	255.9	-0.2
ssr	409.3	408.8	-0.1
ssr-commerce	373.2	372.7	-0.1

SSR Progress

Use case	SSR (#)	CSR (#)	Progress (%)
search	39	44	89
recommendation	0	4	0
case-assist	0	6	0
insight	0	27	0
commerce	0	15	0

Detailed logs

search : buildInteractiveResult
search : buildInteractiveInstantResult
search : buildInteractiveRecentResult
search : buildInteractiveCitation
search : buildGeneratedAnswer
recommendation : missing SSR support
case-assist : missing SSR support
insight : missing SSR support
commerce : missing SSR support

[louis-bompart]

Todo:

• creates dedicated cdn dist folder/target (that is not used by NPM at all)
• fold browser exports path onto node exports path.
  • update entrypoint documentation.

Blocked by:

• replace @microsoft/fetch-event-source
• amend exponential-backoff so that it either includes its sources, or use inline-source-map
  • check what other "big" packages do.

[louis-bompart]

Bundle size will be broken for this PR because we changed the directory from dist/browser to cdn

[louis-bompart]

Too big. Needs to be splitted.