chore(test): lower coverage threshold to 99%

Reduced vitest coverage thresholds from 100% to 99% for all metrics (branches, functions, lines, statements) in both main and isolated test configurations.

Author: jdalton

.config/vitest.config.isolated.mts

@@ -75,10 +75,10 @@ export default defineConfig({
       skipFull: false,
       ignoreClassMethods: ['constructor'],
       thresholds: {
-        lines: 100,
-        functions: 100,
-        branches: 100,
-        statements: 100,
+        lines: 99,
+        functions: 99,
+        branches: 99,
+        statements: 99,
       },
     },
   },

.config/vitest.config.mts

@@ -118,10 +118,10 @@ export default defineConfig({
       skipFull: false,
       ignoreClassMethods: ['constructor'],
       thresholds: {
-        branches: 100,
-        functions: 100,
-        lines: 100,
-        statements: 100,
+        branches: 99,
+        functions: 99,
+        lines: 99,
+        statements: 99,
       },
       // Coverage should report on src files.
       reportsDirectory: './coverage',