chore(release): 0.12.1 -- coord-send stops silently falling back to a stale copy

Version sync across plugin.json, package.json, README badge, CHANGELOG and
all three skill frontmatters, plus the 156 -> 159 selftest-count references
that follow from the previous commit's three new checks.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YJMJanRHkUhEf9EYxMpbM5

skills/board/SKILL.md

@@ -14,7 +14,7 @@ description: >-
   user names no repo and no tool — choosing *between* repos is this skill. Not for
   "where were we" inside the current repo: that is this repo's own STATE.md,
   already injected at session start.
-version: "0.12.0"
+version: "0.12.1"
 ---
 
 # board — which repo deserves the next session

skills/coord-send/SKILL.md

@@ -15,7 +15,7 @@ description: >-
   covers retiring a broadcast that has become wrong or obsolete: "retract that
   broadcast", "that announcement is outdated, pull it", "trekk tilbake kringkastingen",
   "den broadcasten er utdatert".
-version: "0.12.0"
+version: "0.12.1"
 ---
 
 # coord-send — natural-language front door for inter-repo messages

skills/route/SKILL.md

@@ -14,7 +14,7 @@ description: >-
   the operator names no model and no tool — choosing the model for the next
   session IS this skill. Not for choosing which REPO gets the next session:
   that is the `board` skill.
-version: "0.12.0"
+version: "0.12.1"
 ---
 
 # route — what the next session should run with