fix(devx): generate the debt re-measure tsconfig outside the repository (#8260)

`--re-measure` wrote `tsconfig.debt-remeasure.json` into each ledgered
package's own directory -- a tracked directory, matched by no .gitignore
rule -- and left it there for the duration of that package's tsc run.
Measured across the ledger that is a ~250s window in which any
`git add -A` in the same worktree stages a live generated file; it
already reached one real commit. The `finally` that removes it was never
the gap, the address was.

The project now goes to a fresh os.tmpdir() directory, which means every
path it emits has to be absolute -- including the typeRoots tsc would
otherwise derive from the config's own location. Without them
packages/cli measures 1 instead of 188, so TS2688 now counts as a broken
measurement rather than as one tidy error.

Refs #8218

Co-authored-by: Claude <noreply@anthropic.com>

Author: hotlong