ci: provide non-failing Redis (abortConnect=false) + placeholder Encryption key for EF migration design-time host

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Jenkinsfile

@@ -175,7 +175,10 @@ pipeline {
             bat 'chcp 65001 >NUL && dotnet tool restore --tool-manifest dotnet-tools.json'
             withEnv([
               "ConnectionStrings__DefaultConnection=${CONN}",
-              "ConnectionStrings__IdentityDbContextConnection=${CONN}"
+              "ConnectionStrings__IdentityDbContextConnection=${CONN}",
+              "Redis__DefaultConnection=localhost:6379,abortConnect=false,connectTimeout=500",
+              "Encryption__CurrentKeyVersion=1",
+              "Encryption__Keys__V1=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="
             ]) {
               // EF Core CLI: `-c` = `--context` (NOT --configuration). --configuration Release 명시.
               bat "chcp 65001 >NUL && dotnet ef database update --project ${EF_CTX_PROJ} --startup-project ${EF_START_PROJ} --context AppDbContext --configuration Release --no-build"