chore(ci): remove qlty-health no-fail once existing qlty debt is resolved

[williaby]

Context

PR #62 added a weekly qlty-health full-codebase scan (.github/workflows/qlty.yml) that runs in informational mode via no-fail: true. This suppresses non-zero exits so the scan never blocks, while pre-existing qlty debt is still present in the codebase.

Task

Once the existing qlty findings surfaced by the weekly health scan are resolved, remove no-fail: true from the qlty-health job so the scheduled scan can fail on regressions (it already runs at fail-level: high).

Acceptance criteria

• Outstanding qlty findings from the weekly health scan are resolved.
• no-fail: true removed from the qlty-health job in .github/workflows/qlty.yml.
• The tracking comment on that job is removed or updated.

Tracked from PR #62 review.