Implement comprehensive frontend integration testing with Playwright

- Add Playwright E2E testing framework with cross-browser support (Chrome, Firefox)
- Create authentication helpers for CalDAV server integration
- Implement calendar interaction helpers with event creation, drag-and-drop, and view switching
- Add comprehensive drag-and-drop test suite with event cleanup
- Configure CI/CD integration with Gitea Actions for headless testing
- Support both local development and CI environments with proper dependency management
- Include video recording, screenshots, and HTML reporting for test debugging
- Handle Firefox-specific timing and interaction challenges with force clicks and timeouts

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/e2e/node_modules/playwright/lib/common/poolBuilder.js

@@ -0,0 +1,85 @@
+"use strict";
+var __defProp = Object.defineProperty;
+var __getOwnPropDesc = Object.getOwnPropertyDescriptor;
+var __getOwnPropNames = Object.getOwnPropertyNames;
+var __hasOwnProp = Object.prototype.hasOwnProperty;
+var __export = (target, all) => {
+  for (var name in all)
+    __defProp(target, name, { get: all[name], enumerable: true });
+};
+var __copyProps = (to, from, except, desc) => {
+  if (from && typeof from === "object" || typeof from === "function") {
+    for (let key of __getOwnPropNames(from))
+      if (!__hasOwnProp.call(to, key) && key !== except)
+        __defProp(to, key, { get: () => from[key], enumerable: !(desc = __getOwnPropDesc(from, key)) || desc.enumerable });
+  }
+  return to;
+};
+var __toCommonJS = (mod) => __copyProps(__defProp({}, "__esModule", { value: true }), mod);
+var poolBuilder_exports = {};
+__export(poolBuilder_exports, {
+  PoolBuilder: () => PoolBuilder
+});
+module.exports = __toCommonJS(poolBuilder_exports);
+var import_fixtures = require("./fixtures");
+var import_util = require("../util");
+class PoolBuilder {
+  constructor(type, project) {
+    this._testTypePools = /* @__PURE__ */ new Map();
+    this._type = type;
+    this._project = project;
+  }
+  static createForLoader() {
+    return new PoolBuilder("loader");
+  }
+  static createForWorker(project) {
+    return new PoolBuilder("worker", project);
+  }
+  buildPools(suite, testErrors) {
+    suite.forEachTest((test) => {
+      const pool = this._buildPoolForTest(test, testErrors);
+      if (this._type === "loader")
+        test._poolDigest = pool.digest;
+      if (this._type === "worker")
+        test._pool = pool;
+    });
+  }
+  _buildPoolForTest(test, testErrors) {
+    let pool = this._buildTestTypePool(test._testType, testErrors);
+    const parents = [];
+    for (let parent = test.parent; parent; parent = parent.parent)
+      parents.push(parent);
+    parents.reverse();
+    for (const parent of parents) {
+      if (parent._use.length)
+        pool = new import_fixtures.FixturePool(parent._use, (e) => this._handleLoadError(e, testErrors), pool, parent._type === "describe");
+      for (const hook of parent._hooks)
+        pool.validateFunction(hook.fn, hook.type + " hook", hook.location);
+      for (const modifier of parent._modifiers)
+        pool.validateFunction(modifier.fn, modifier.type + " modifier", modifier.location);
+    }
+    pool.validateFunction(test.fn, "Test", test.location);
+    return pool;
+  }
+  _buildTestTypePool(testType, testErrors) {
+    if (!this._testTypePools.has(testType)) {
+      const optionOverrides = {
+        overrides: this._project?.project?.use ?? {},
+        location: { file: `project#${this._project?.id}`, line: 1, column: 1 }
+      };
+      const pool = new import_fixtures.FixturePool(testType.fixtures, (e) => this._handleLoadError(e, testErrors), void 0, void 0, optionOverrides);
+      this._testTypePools.set(testType, pool);
+    }
+    return this._testTypePools.get(testType);
+  }
+  _handleLoadError(e, testErrors) {
+    if (testErrors)
+      testErrors.push(e);
+    else
+      throw new Error(`${(0, import_util.formatLocation)(e.location)}: ${e.message}`);
+  }
+}
+// Annotate the CommonJS export names for ESM import in node:
+0 && (module.exports = {
+  PoolBuilder
+});