DC-053 follow-ups (queue item 2b). Three small fixes to the caddy-upstream-watcher: 1. verifiedViaBridge flag: a loopback upstream whose PRIOR probe succeeded via host-gateway proves the bridge CAN reach the host. A later failed probe is then near-conclusive evidence the upstream itself went dead. The DC-053 code unconditionally marked loopback failures as unverifiable, throwing away this signal. Now: track verifiedViaBridge per-upstream and treat verified-then-failed as down (count failures, open incident after DEAD_AFTER_MS=5min). 2. IN_CONTAINER=false kill-switch test (B-grade polish, folded into same commit per conjoint-commit anti-pattern). 3. git.sami intermittent ENOTFOUND (~2/h in ssl-monitor TLS handshake): pin git.sami -> 100.121.150.22 (DNS2 Tailscale) in container /etc/hosts via --add-host in start.sh. Existing comment explicitly forbids pinning to DNS3/100.81.59.99 (no HTTPS listener there); DNS2/100.121.150.22 is correct (Caddy serves git.sami on DNS2:443 and routes to DNS3:3030 internally). GLM-5.3 judge round 1 (208s, 6 tool calls, on-disk verified): grade B, all 25 tests green, no blocking issues, 3 LOW polish suggestions. Folded two actionable LOWs (persistence + JSDoc) into this commit: - verifiedViaBridge now persisted in _saveState/_restoreUpstreamStates so a known-good loopback upstream stays labeled across container restarts (1-tick blip becomes 0-tick). - snapshot() gained JSDoc describing the verifiedViaBridge semantic for dashboard consumers. Third LOW (long-term: prefer host-side liveness signal from Caddy) is a roadmap note, not actionable now. Tests: 1921/1921 (was 1910; +11 net: 6 new for items 2b-a/2b-b/persistence + 5 previously-skipped baseline). Full suite 86/86 green.