fix: forced monorepo splits fail during cleanup

[imorland]

Two bugs in monorepo:split --force, both found by using it regularly on the Flarum monorepo.

Cleanup deletes a branch that a forced split never creates

splitAndPush() only creates the <remote>-tmp branch on the non-forced path:

if (force) {
  execSync(`git push --force ${pushArgs}`, { cwd });   // pushes the sha directly
} else {
  execSync(`git switch -c ${tmpBranch} ${sha1}`, { cwd });
  …
}

but cleanupBranchAndRemote() ran git branch -D <remote>-tmp unconditionally. So every forced split threw once all the pushes had already succeeded — the work was done, the command still ended in an error.

--force ignored --no-interaction

The force confirmation is a confirm param with initial: false. In non-interactive mode PromptsIO::getParam() returns the initial value rather than prompting, so the answer was always "no" and monorepo:split --force --no-interaction reliably printed "Decided not to force push" and did nothing.

That's precisely the flag combination a script or CI job would use, and it silently no-oped. The confirmation is now skipped when the operator has already asked not to be prompted — --no-interaction means "don't ask me", so a forced split proceeds.

Worth being deliberate about: this makes --force --no-interaction genuinely force-push to every split repo without confirmation. That is the intent of the flag pair, and the guard remains for interactive use.

Verification

yarn test — 22 suites, 176 tests, Prettier clean. Both paths exercised by hand against the Flarum monorepo on Apple silicon over an extended period.