feat(kvb-git-hotfix): share hotfixes in the register and sync before every action

The Maintainer messaged every agent about every hotfix, waking each for a full turn. Hotfixes are now register rows hotfix/<slug> (repository identity by git common dir and normalized origin URL, branch, sha, PR, failing-line signature, targets, stage), written with hotfix.py add/update and queried only when an agent acts, never by cron: pending lists merged hotfixes missing from HEAD (filtered by targets) and open ones; match finds hotfixes whose signature fits a failing line, evaluated in one worker under a shared deadline; void tells gate.py run, before every target, when a merged hotfix missing from HEAD makes the rest of the run worthless (exit 3), the operator's one exception to never cutting a job short; sync fetches first, then under the worktree locks merges origin/<default> and every base up the funnel chain recorded with rasci.py set --base, refusing a detached or foreign branch, a diverged base or a busy worktree, aborting cleanly on a conflict.

gate.py gains hold, which runs any heavy command, deploys included, under the worktree lock, forwards signals, returns the command's code and exits 75 when busy; run holds the same lock and takes the sync lock shared. kvb-check-gate, kvb-ci-triage, kvb-org-organize (Peer protocol, capacity), kvb-org-coordinate and kvb-org-split follow; rasci gaps, wsjf and artifacts skip hotfix and operator rows. Three independent skeptic rounds found 34 defects (three of them high), all fixed with tests; negative controls fail against the earlier code.

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

README.md

@@ -57,6 +57,7 @@ flowchart LR
   git --> git_update_branches[kvb-git-update-branches]
   git --> git_branch_gc[kvb-git-branch-gc]
   git --> git_changelog[kvb-git-changelog]
+  git --> git_hotfix[kvb-git-hotfix]
   check --> check_legal[kvb-check-legal]
   check --> check_security[kvb-check-security]
   check --> check_principles[kvb-check-principles]
@@ -149,6 +150,7 @@ flowchart LR
     update_branches[kvb-git-update-branches]
     branch_gc[kvb-git-branch-gc]
     changelog[kvb-git-changelog]
+    hotfix[kvb-git-hotfix]
   end
   subgraph cat_check [check]
     advocate[kvb-check-legal]
@@ -232,6 +234,10 @@ flowchart LR
   confidence --> gate
   pr_label --> gate
   gate --> democracy
+  gate --> hotfix
+  triage --> hotfix
+  democracy --> hotfix
+  hotfix --> rasci
   confidence -. objective .-> autotune
 
   coordinate --> democracy