chore: sync Code UX 0.9.5 back to dev

[numnx]

Summary

Synchronize the published 0.9.5 release lineage from main back into dev so new feature branches retain the release version, scoped-package registry encoding fix, and dependency-coupled compatibility checks.

Included release work

• Version bump to 0.9.5.
• Complete npm registry path encoding for scoped provider CLI packages, resolving the CodeQL finding from the release PR.
• Compatibility contexts for historical main ruleset names, each gated by the corresponding real test, security, package, orchestration, E2E, or release-candidate dependency.
• Documentation and workflow-health tests for the compatibility behavior.

Validation

• Release PR #2806 passed typecheck, backend coverage, dashboard tests, dependency audit, build, CodeQL, documentation smoke, 18 cross-platform Playwright shards, orchestration, npm install smoke, and desktop release-candidate packaging.
• The sync merge produces the same filesystem tree as release commit 6ef8c97f79bc30abc0d09d2b640a43f2bb2bf1b8.

Risk and rollback

• Risk is low: this is a lineage sync with no tree delta from the validated release commit.
• Roll back by reverting this merge commit on dev; do not rewrite branch history.