TypeScript checking rolled back to the old path
Restore in-process TypeScript checker as default — Deno reverted the native tsc migration and made deno check use the in-process checker again. That restores the previous behavior for --watch rechecking, --doc and --doc-only snippet validation, and the expected diagnostics/spec output while the broader migration is rolled back.
Other misc changes
- Removed native tsc CI cache/download steps from generated workflows.
- Updated CLI/type-checker/tsconfig plumbing to route back through the old checker path.
- Refreshed integration/spec expectations across check, npm, watcher, and related tests.