docs(keycloak-session-store): take the sentences out of the diagram canvases

The skill says drawings carry names and sentences go in <desc> and the
paragraph beside the figure. I put sentences in node details and edge labels
instead, and 27 of the 28 diagrams shipped with prose inside the canvas —
"예측 다섯 개가 틀렸다", "아홉 번 조용히 실패했다", "막혀서 닿지 않는다".

Only label and details render on the canvas; description does not. So every
sentence moved to a noun phrase and the meaning stays in description, which
was already carrying it.

  막혀서 닿지 않는다              -> 차단
  아홉 번 조용히 실패했다         -> 조용한 실패 9건
  예측 다섯 개가 틀렸다           -> 틀린 예측 5건
  로그아웃이 정리하지 않는다      -> 로그아웃 미정리
  볼륨이 없으면 여기까지다        -> 볼륨 없음

Three node labels were sentences too and became names: 세션 스냅샷, 예측
선기록, 대조군 확보.

What stays is what the rules protect — identifiers, commands and measured
values: PRIMARY KEY (client_registration_id, principal_name),
ValidationFailedException: 1 changesets check sum, nginx -t && nginx -s
reload, SET LOCAL synchronous_commit TO OFF. Those are names of things, not
prose about them.

294 canvas strings across 28 diagrams, none matching a sentence ending,
average 11 characters. All 28 still lint clean and re-rendered.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/keycloak-session-store/final/.techviz/c2-backchannel-both-sides/spec.json

@@ -54,7 +54,7 @@
       "emphasis": "warning",
       "description": "클라이언트 설정. 비어 있었다.",
       "details": [
-        "Keycloak 은 부를 주소를 모른다"
+        "주소 없음"
       ],
       "evidence": [
         {
@@ -90,7 +90,7 @@
       "emphasis": "warning",
       "description": "그대로 남는다.",
       "details": [
-        "네트워크는 200 으로 닿는다"
+        "네트워크 도달 200"
       ],
       "evidence": [
         {
@@ -106,7 +106,7 @@
       "id": "l-c",
       "from": "logout",
       "to": "kc-config",
-      "label": "통지할 주소를 찾는다",
+      "label": "통지 주소 조회",
       "kind": "request",
       "evidence": [
         {
@@ -120,7 +120,7 @@
       "id": "c-e",
       "from": "kc-config",
       "to": "app-endpoint",
-      "label": "주소가 있어야 부른다",
+      "label": "호출 (주소 필요)",
       "kind": "blocked",
       "evidence": [
         {
@@ -134,7 +134,7 @@
       "id": "e-s",
       "from": "app-endpoint",
       "to": "app-session",
-      "label": "받을 곳이 있어야 지운다",
+      "label": "세션 삭제 (엔드포인트 필요)",
       "kind": "blocked",
       "evidence": [
         {