chore(test): replace jest-environment-obsidian with jsdom for Jest 30.4.x compatibility

jest-environment-obsidian@0.0.1 bundles jest-mock@29 internally, which lacks
the clearMocksOnScope method added in Jest 30.4.x. Switches to jest-environment-jsdom
and adds a setup file providing the Obsidian DOM globals and prototype extensions
that the environment previously injected.

jest.config.js

@@ -1,6 +1,7 @@
 /** @type {import('ts-jest').JestConfigWithTsJest} */
 module.exports = {
-  testEnvironment: 'jest-environment-obsidian',
+  testEnvironment: 'jest-environment-jsdom',
+  setupFiles: ['./src/__tests__/setup.ts'],
   verbose: true,
   preset: 'ts-jest',
   transform: {
@@ -14,6 +15,7 @@ module.exports = {
       },
     ],
   },
+  testMatch: ['**/__tests__/**/*.test.ts'],
   moduleFileExtensions: ['js', 'd.ts', 'ts'],
   coverageReporters: ['html', 'text', 'cobertura'],
   collectCoverageFrom: ['src/**/*.{js,jsx,ts,tsx}', '!<rootDir>/node_modules/'],

src/__tests__/setup.ts

@@ -0,0 +1,101 @@
+function _createEl(
+  tag: string,
+  info?: { cls?: string; text?: string; type?: string; attr?: Record<string, string> },
+  callback?: (el: HTMLElement) => void
+): HTMLElement {
+  const el = document.createElement(tag);
+  if (info?.cls) el.className = info.cls;
+  if (info?.text) el.textContent = info.text;
+  if (info?.type && el instanceof HTMLInputElement) el.type = info.type;
+  if (info?.attr) Object.entries(info.attr).forEach(([k, v]) => el.setAttribute(k, v));
+  if (callback) callback(el);
+  return el;
+}
+
+// Global Obsidian DOM helpers
+(globalThis as any).createEl = _createEl;
+(globalThis as any).createDiv = (info?: any, callback?: any) => _createEl('div', info, callback);
+(globalThis as any).createSpan = (info?: any, callback?: any) => _createEl('span', info, callback);
+
+// Node prototype extensions
+(Node.prototype as any).createEl = function (tag: any, info?: any, callback?: any) {
+  const el = _createEl(tag, info, callback);
+  this.appendChild(el);
+  return el;
+};
+(Node.prototype as any).createDiv = function (info?: any, callback?: any) {
+  return (this as any).createEl('div', info, callback);
+};
+(Node.prototype as any).createSpan = function (info?: any, callback?: any) {
+  return (this as any).createEl('span', info, callback);
+};
+(Node.prototype as any).empty = function () {
+  while (this.firstChild) this.removeChild(this.firstChild);
+};
+(Node.prototype as any).detach = function () {
+  this.parentNode?.removeChild(this);
+};
+(Node.prototype as any).appendText = function (val: string) {
+  this.appendChild(document.createTextNode(val));
+};
+
+// Element prototype extensions
+(Element.prototype as any).find = function (selector: string) {
+  return this.querySelector(selector);
+};
+(Element.prototype as any).findAll = function (selector: string) {
+  return Array.from(this.querySelectorAll(selector));
+};
+(Element.prototype as any).getText = function () {
+  return this.textContent;
+};
+(Element.prototype as any).setText = function (val: string) {
+  this.textContent = val;
+};
+(Element.prototype as any).addClass = function (...classes: string[]) {
+  this.classList.add(...classes);
+};
+(Element.prototype as any).removeClass = function (...classes: string[]) {
+  this.classList.remove(...classes);
+};
+(Element.prototype as any).toggleClass = function (classes: string | string[], value: boolean) {
+  const list = Array.isArray(classes) ? classes : [classes];
+  list.forEach((cls) => this.classList.toggle(cls, value));
+};
+(Element.prototype as any).hasClass = function (cls: string) {
+  return this.classList.contains(cls);
+};
+(Element.prototype as any).setAttr = function (name: string, value: string) {
+  this.setAttribute(name, String(value));
+};
+(Element.prototype as any).getAttr = function (name: string) {
+  return this.getAttribute(name);
+};
+
+// HTMLElement prototype extensions
+(HTMLElement.prototype as any).show = function () {
+  this.style.display = '';
+};
+(HTMLElement.prototype as any).hide = function () {
+  this.style.display = 'none';
+};
+
+// String prototype extensions
+(String.prototype as any).contains = function (target: string) {
+  return this.includes(target);
+};
+
+// Array prototype extensions
+(Array.prototype as any).contains = function (item: any) {
+  return this.includes(item);
+};
+(Array.prototype as any).first = function () {
+  return this[0];
+};
+(Array.prototype as any).last = function () {
+  return this[this.length - 1];
+};
+(Array.prototype as any).remove = function (target: any) {
+  const i = this.indexOf(target);
+  if (i > -1) this.splice(i, 1);
+};