feat(kvb-check-confidence, kvb-git-pr-label): declare 90/5 only after the quality gate

Operator rule of 2026-11-03: nothing is declared 90/5 (fix confidence of at least 90 %, break risk under 5 %) before the project's full quality gate passed on the exact head, make quality-high in infinito-nexus; until then the numbers are provisional and the missing gate is the residual. The 90/5 label follows the same gate, and a hotfix takes the next free gate slot. #1365 had the label after targeted tests only; #1357 before it left main red on a lint-only check.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

skills/kvb-git-pr-label/SKILL.md

@@ -13,7 +13,9 @@ holds:
   name the run or issue.
 - **`90/5`**: the pull request meets the bar of the `kvb-org-split` skill (fix
   confidence of at least 90 %, break risk under 5 %), from the
-  `kvb-check-confidence` numbers in its body or freshly assessed.
+  `kvb-check-confidence` numbers in its body or freshly assessed, and only
+  after the project's full quality gate passed on the PR's exact head; a
+  hotfix takes the next free gate slot.
 
 ## Procedure