ci: scope coverage to unit-testable code, gate at 100%

The platform glue (the LSP factory + connection provider) needs a running IDE
and is covered by the Plugin Verifier, not unit tests. Exclude it from Kover so
coverage reflects the unit-testable logic — now 100% — and enforce that with a
koverVerify minBound(100) rule.

Author: maxonfjvipon

build.gradle.kts

@@ -67,11 +67,26 @@ detekt {
 
 kover {
     reports {
+        filters {
+            excludes {
+                // Platform glue — instantiable only inside a running IDE, so
+                // it's exercised by the Plugin Verifier, not by unit tests.
+                classes(
+                    "com.xslint.jetbrains.XslintLanguageServerFactory",
+                    "com.xslint.jetbrains.XslintLanguageServer",
+                )
+            }
+        }
         total {
             xml {
                 onCheck = true
             }
         }
+        verify {
+            rule {
+                minBound(100)
+            }
+        }
     }
 }