TypeScript 7.0 is the native compiler and ships no JavaScript API. The
earlier changes in this series already moved everything that transpiled
on the fly (script/ and spec/) onto Node's own type stripping, so what
is left here is the compiler swap itself:
* typescript ^5.8.3 -> ^7.0.2.
* build/bundle/typecheck.mjs spawns tsc instead of driving the compiler
API (the rootDir/private-field diagnostics it used to filter out are
handled by tsconfig.electron.json setting rootDir to the parent
checkout instead).
* tsconfig.json drops the removed baseUrl option and anchors the paths
mapping explicitly; tsconfig.default_app.json moves off the removed
"node" module resolution; `declare module NodeJS` becomes a namespace.
* A few lib/, spec and docs snippets wrap Buffers for the stricter
Buffer/ArrayBuffer typings that Blob now expects.
Co-authored-by: Claude <noreply@anthropic.com>
