fix(cli): apply client selector to registry integrations (#1798)

[rarepops]

What does this PR do?

Fixes #1798.

--clients previously filtered only the legacy client table, so registry-backed clients such as Qoder and Rovo Dev were still detected and configured. This change makes registry stable IDs part of the selector vocabulary and applies the same restriction to registry detection output and installation.

The selector remains restrictive: it configures only selected clients that are detected, and does not force-enable undetected clients.

Validation covered the sanitizer build and both selector regressions. The full CLI suite passes with 283 tests. clang-format 20.1.8 and git diff --check pass; focused cppcheck reports only pre-existing style findings in test helpers and older test code.

Checklist

• Every commit is signed off (git commit -s) - required, CI rejects unsigned commits (DCO, see CONTRIBUTING.md)
• Tests pass locally (cli: 283 passed)
• Lint passes (make -f Makefile.cbm lint-ci) - upstream lint / lint and lint / lint-mem checks pass
• New behavior is covered by a test (reproduce-first for bug fixes)

[github-actions]

Thanks for opening this — it has been seen, and it is queued.

This note is automated, but it is not a brush-off: it exists so you know where your PR stands instead of having to guess from silence.

Current review status: working through a backlog. 0.9.1-rc.1 is out, so the release freeze that held reviews is over — but it left a large queue of open pull requests behind it, and we are reading through them oldest-first. The background is in discussion #1144.

What that means for this PR, concretely:

• It will not be closed for inactivity. No stale bot touches pull requests here.
• It may still sit a while before a human reads it. That is on us, not on you.
• Older PRs are read first, so a recent one is not being skipped — it is behind a queue.

Things that will genuinely speed it up whenever review does happen:

• Keep it rebased on main — the tree is moving quickly right now, and a conflicting branch cannot be reviewed as the diff you intended.
• Get CI green, or say which failures you believe are pre-existing.
• Keep the change to one claim. Bundled features and refactors get split before they get merged, which costs you a round trip.
• Every commit needs a sign-off (git commit -s) — CI enforces DCO.

If this fixes a bug, a reproduction we can run is worth more than a description of the symptom.

Thanks for contributing, and sorry in advance for the wait.