Route the body of each `<style>` tag in an HTML module through the CSS
pipeline as a virtual `data:text/css` module with `exportType: "text"`
so `url()` and `@import` references are resolved relative to the HTML
file. At render time the processed CSS text is written back into the
original tag's content range, leaving the `<style>` wrappers in place.
`<style type="text/css">` and `<style>` with no `type` are processed;
non-CSS `type` values are passed through unchanged.

- `CssGenerator` exposes the merged CSS source on the `css-text` codegen
  data channel when `exportType: "text"`, so consumers can read the
  processed CSS without going through the JS string literal wrapper.
- `HtmlInlineStyleDependency` carries the inline CSS as a `data:` URL
  request and replaces the original content range with the processed
  CSS at template-apply time.
- `HtmlParser` detects `<style>` rawtext, extracts the body, and skips
  the walker past `</style>` so the body is never reparsed as HTML.
- `ConcatenatedModule` now propagates inner-module
  `codeGenerationDependencies` so the inline CSS sub-modules are
  guaranteed to be code-generated before the enclosing concatenated
  module's templates run.

https://claude.ai/code/session_01NVjep3RpridezBWaHT2wYD

Three fixes from the Copilot review of #20962:

1. Register `HtmlInlineStyleDependency` in `internalSerializables.js`.
   The serializer's class loader only resolves keys listed there, so
   filesystem-cached compilations containing an inline-style dep would
   fail to deserialize without this entry.

2. Gate the `<style>` rawtext → `data:text/css` conversion on
   `experiments.css`. With `experiments.html` alone the CSS rules and
   `CssModulesPlugin` aren't installed; the data URI would resolve as a
   plain module and the inline style body would be replaced with an
   empty string. Pass a `css` flag through `HtmlModulesPlugin` into
   `HtmlParser`. When it's off, the parser still skips past
   `</style>` so the rawtext isn't reparsed as HTML, but no dependency
   is emitted.

3. Preserve the HTML file's directory as the resolution context for
   the virtual CSS module. Without help, the data URI's synthetic
   `context` becomes `getContext("data:text/...")` (= `"data:text/"`),
   so nested `url(...)` / `@import` references would resolve against
   that nonsense path and only work by accident when the compiler
   context happens to match the HTML directory. Register a
   `resolveForScheme.for("data")` hook in `HtmlModulesPlugin` that
   copies the issuer's context onto the resolved resource data for
   dependencies in the `"html-style"` category, leaving other
   `data:` URI uses unchanged.

Test fixtures:
- `style-tag-no-css` — inline `<style>` body round-trips verbatim
  when `experiments.css` is off.
- `style-tag-context` — HTML file lives in a subdirectory while the
  webpack context is the parent; relative `url("./pixel.png")` in
  inline CSS must resolve to the HTML directory.

https://claude.ai/code/session_01NVjep3RpridezBWaHT2wYD

The default rule added for inline `<style>` (`dependency: "html-style"`,
`parser: { exportType: "text" }`) shows up in the snapshots taken by
`Defaults.unittest.js` for the two cases where `experiments.css` and
`experiments.html` are both on (`cache.filesystem + futureDefaults` and
`futureDefaults` alone). Refresh both inline snapshots and add the
ConfigCacheTestCases snapshot for the new `style-tag` fixture.

https://claude.ai/code/session_01NVjep3RpridezBWaHT2wYD

Every existing `test/configCases/html/*` fixture has an `eol=lf` entry
in `.gitattributes` so Windows checkouts (where `core.autocrlf=true` is
common) don't convert HTML/JS line endings to CRLF. Without it the
inline-style body picked up by `HtmlParser` includes `\r\n`, which
encodes to `%0D%0A` in the data URI and drifts the source-comment
header that the snapshot assertions check.

Add the same pin for `style-tag`, `style-tag-context`, and
`style-tag-no-css`.

https://claude.ai/code/session_01NVjep3RpridezBWaHT2wYD