Stability checkpoint — UI 1.0.51 (CI hygiene wave : 2 fixes confirmed, 2 partial)

Captures !120 + !121 + !122 + !123 (UI CI cleanup waves) :

✅ CONFIRMED FIXED on main #2478522873 (this commit) :
- grype:scan : /grype absolute path → SUCCESS, shield removed
- dockle    : svc tarball pattern → SUCCESS, shield removed

🟡 PARTIAL PROGRESS (allow_failure shielded, still fail) :
- sonarcloud : heap 4096→8192 + retry runner_system. Still flakes
  with WebSocket connection closed abnormally. Next escalation :
  -Dsonar.javascript.workerCount=2 OR scanner image upgrade.
- e2e:kind : 4-stage pivot (--wait → pg_isready loop → init-sonar.sql
  strip). postgres now boots OK (was crashing on init-sonar dir
  bind-mount). NEW issue surfaced : Spring Boot Flyway
  'Connection attempt failed' despite pg_isready green — Docker
  network connect to compose bridge probably failing silently.
  Next : add explicit network-connect verification + getent hosts db.

Net : 2/4 UI CI debt items fully closed (was 0/4 this morning).
2 remaining items have known root causes documented for next wave.