CC Adoption Milestone Zero-Out — close verdicts

Final sweep of the "CC adoption" milestone after the 4-workstream 2.1.171–175 plan (6 PRs, 16 issues). Each card carries the evidence for its verdict — click to expand. One issue stays open by design.

Floor context: supported_floor = 2.1.170 (owner override, expires 2026-09-07). Anything targeting CC < 2.1.170 is below the support window — moot by policy (shared/rules/cc-support-policy.md).