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.Transport.Tests/Import/BundleImporterLoadTests.cs

@@ -130,7 +130,7 @@ public sealed class BundleImporterLoadTests
         var manifest = builder.Build(
             sourceEnvironment: "dev",
             exportedBy: "alice",
-            scadaLinkVersion: "1.0.0",
+            scadaBridgeVersion: "1.0.0",
             encryption: null,
             summary: new BundleSummary(content.Templates.Count, 0, 0, 0, 0, 0, 0, 0, 0),
             contents: Array.Empty<ManifestContentEntry>(),
@@ -152,7 +152,7 @@ public sealed class BundleImporterLoadTests
         var manifest = builder.Build(
             sourceEnvironment: "dev",
             exportedBy: "alice",
-            scadaLinkVersion: "1.0.0",
+            scadaBridgeVersion: "1.0.0",
             encryption: seed,
             summary: new BundleSummary(content.Templates.Count, 0, 0, 0, 0, 0, 0, 0, 0),
             contents: Array.Empty<ManifestContentEntry>(),
@@ -471,7 +471,7 @@ public sealed class BundleImporterLoadTests
         var manifest = rig.ManifestBuilder.Build(
             sourceEnvironment: "dev",
             exportedBy: "alice",
-            scadaLinkVersion: "1.0.0",
+            scadaBridgeVersion: "1.0.0",
             encryption: null,
             summary: new BundleSummary(1, 0, 0, 0, 0, 0, 0, 0, 0),
             contents: Array.Empty<ManifestContentEntry>(),