Refactor to unify scripts/categories as Executable

This commit consolidates scripts and categories under a unified
'Executable' concept. This simplifies the architecture and improves code
readability.

- Introduce subfolders within `src/domain` to segregate domain elements.
- Update class and interface names by removing the 'I' prefix in
  alignment with new coding standards.
- Replace 'Node' with 'Executable' to clarify usage; reserve 'Node'
  exclusively for the UI's tree component.

tests/unit/application/Parser/Executable/Script/Validation/Rules/CodeValidationRuleTestRunner.ts

@@ -0,0 +1,36 @@
+import { it, expect } from 'vitest';
+import type { ICodeValidationRule, IInvalidCodeLine } from '@/application/Parser/Executable/Script/Validation/ICodeValidationRule';
+import type { ICodeLine } from '@/application/Parser/Executable/Script/Validation/ICodeLine';
+
+interface ICodeValidationRuleTestCase {
+  testName: string;
+  codeLines: readonly string[];
+  expected: readonly IInvalidCodeLine[];
+  sut: ICodeValidationRule;
+}
+
+export function testCodeValidationRule(testCases: readonly ICodeValidationRuleTestCase[]) {
+  for (const testCase of testCases) {
+    it(testCase.testName, () => {
+      // arrange
+      const { sut } = testCase;
+      const codeLines = createCodeLines(testCase.codeLines);
+      // act
+      const actual = sut.analyze(codeLines);
+      // assert
+      function sort(lines: readonly IInvalidCodeLine[]) { // To ignore order
+        return Array.from(lines).sort((a, b) => a.index - b.index);
+      }
+      expect(sort(actual)).to.deep.equal(sort(testCase.expected));
+    });
+  }
+}
+
+function createCodeLines(lines: readonly string[]): ICodeLine[] {
+  return lines.map((lineText, index): ICodeLine => (
+    {
+      index: index + 1,
+      text: lineText,
+    }
+  ));
+}