dts: declarations written by a standalone tsc run are not augmented #706

Follow-up to #694. Found while reviewing #697.

#697 adds Ivy members to the .d.ts files that rolldown-plugin-dts, tsdown (.d.mts and .d.cts), vite-plugin-dts and @rollup/plugin-typescript write. A plain tsc -p tsconfig.lib.json run is outside the Vite / Rolldown build, so no plugin hook sees it. Libraries built that way still ship plain classes, and consumers fail with NG2012 (as in #681). The README lists this as not covered.

Possible directions:

• A small CLI / exported function that runs the compiler over the sources and injects members into an existing declaration dir, using the same matchDtsSources + injectDtsFile as the plugin's disk pass.
• Document running the build with a declaration plugin instead of a separate tsc step.