refactor: scrub residual ScadaLink refs → ScadaBridge (env vars, config keys, assembly name, SQL login)

Renames the 13 SCADALINK_* runtime env vars → SCADABRIDGE_*, the ScadaLink__
.NET config keys → ScadaBridge__, the stale ScadaLink.Host.exe assembly name
→ ZB.MOM.WW.ScadaBridge.Host.exe, the scadalink_app SQL login → scadabridge_app,
and residual identifiers/comments/docs. Migration records (prior rename
tooling/design, DB-rename helper, this scrub script) carved out.

Adds tools/scrub-scadalink-refs.sh.

tests/ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests/Audit/AuditLogPageTests.cs

@@ -64,7 +64,7 @@ public class AuditLogPageTests
         {
             throw new InvalidOperationException(
                 "AuditDataSeeder cannot reach MSSQL at localhost:1433 — bring up infra/docker-compose and docker/deploy.sh, " +
-                "or set SCADALINK_PLAYWRIGHT_DB to a reachable connection string.");
+                "or set SCADABRIDGE_PLAYWRIGHT_DB to a reachable connection string.");
         }
 
         var runId = Guid.NewGuid().ToString("N");