fix(angular-rspack): keep class field closures per instance in minified builds

[leosvelperez]

Current Behavior

Production builds from @nx/angular-rspack and @nx/rspack can break classes whose field initializers pass a callback to a helper. Every instance ends up calling the callback of the last instance created.

function wrap(cb) { return () => cb(); }
class C { static n = 0; id = ++C.n; v = wrap(() => this.id); }
[new C(), new C(), new C()].map((c) => c.v()); // unminified: 1,2,3; minified: 3,3,3

The SWC minifier inlines the helper and assigns the callback to a variable that all instances share. In Angular apps this breaks injectVirtualizer from @tanstack/angular-virtual when a page has more than one virtual list. In @nx/rspack apps, the default swc-loader rule compiles app code down to ES5, so there the bug hits dependencies that ship native class fields.

Expected Behavior

Each instance keeps its own callback in minified production builds, for browser and server builds.

Related Issue(s)

Fixes #37050

Implementation Notes

• Both minimizers set compress: { inline: 0, reduce_funcs: false }. Either flag alone still miscompiles. Rspack keeps adding passes: 2 to the object.
• On a larger Angular Material app, gzip size went down 0.12% and raw size went up 0.43%. Build time stayed within noise.
• Other minimizers: Terser fixes it too, but production builds took 1.9x as long. The esbuild output grew 116%, because its transform keeps unused code inside Rspack's module functions. The oxc-minify package is labeled alpha and has open miscompile reports.
• Other settings: compress: false grows raw output 167% to 176%, and concatenateModules: false misses helpers in the same file. Swapping reduce_funcs: false for reduce_vars: false works but adds 1.8% gzip.
• The defect is in the SWC minifier, reported upstream as es/minifier: class field callback shared across instances after helper inlining swc-project/swc#12380. It reproduces on rspack 1.3.5, 1.6.8, 2.0.4 and 2.2.4, and on @swc/core 1.16.2 and the latest nightly. The options can go once an rspack release ships the fix.
• Not covered: @nx/rspack projects whose composePlugins config replaces optimization.minimizer, such as the generated Nest config.

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