feat: support extractComments in swcMinify

[kdy1]

This wires extractComments into TerserPlugin.swcMinify for SWC builds that support comment extraction.

What changed:

• normalize serializable extractComments conditions for SWC (boolean, "some", "all", string patterns, RegExp without flags, and object conditions that resolve to those forms)
• preserve legal comments by default when extractComments: false is used with swcMinify
• surface result.extractedComments back to the plugin so existing filename/banner handling keeps working
• error clearly for unsupported function conditions and flagged regular expressions
• update the README warning to document the supported subset
• add swcMinify coverage for default extraction, object { condition, filename, banner }, disabled extraction, and unsupported function conditions
• remove the explicit @swc/core runtime version gate and rely on the installed SWC build to accept or reject the forwarded option

Verification:

• npm run build
• npx jest test/minify-option.test.js --runInBand
• npm run lint:code -- src/utils.js test/minify-option.test.js
• npx prettier --check README.md src/utils.js test/minify-option.test.js types/utils.d.ts

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: kdy1 / name: DongYun Kang (60e2351, b3939e4, c43d001, d98960a)

[kdy1]

Sorry I made a mistake with AI (codex).

My intention was to open this after publishing a new version of SWC.

I'll undraft this after publishing a new version.

[evenstensberg]

@kdy1 could you sign the CLA?

[alexander-akait]

@kdy1 feel free to ping when it was ready and we will make a release

[kdy1]

Sorry for the delay. I'm trying to deploy (again) it with https://github.com/swc-project/swc/actions/runs/24608184505

The previous run failed in a strange way.

[kdy1]

@alexander-akait I think this PR is good to go. Thank you for waiting 😄

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.76%. Comparing base (783427c) to head (60e2351).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #665   +/-   ##
=======================================
  Coverage   96.76%   96.76%           
=======================================
  Files           3        3           
  Lines         340      340           
  Branches      126      125    -1     
=======================================
  Hits          329      329           
  Misses         11       11           

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