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/runner/failureTracker.js

@@ -0,0 +1,76 @@
+"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 failureTracker_exports = {};
+__export(failureTracker_exports, {
+  FailureTracker: () => FailureTracker
+});
+module.exports = __toCommonJS(failureTracker_exports);
+class FailureTracker {
+  constructor(_config) {
+    this._config = _config;
+    this._failureCount = 0;
+    this._hasWorkerErrors = false;
+  }
+  canRecoverFromStepError() {
+    return !!this._recoverFromStepErrorHandler;
+  }
+  setRecoverFromStepErrorHandler(recoverFromStepErrorHandler) {
+    this._recoverFromStepErrorHandler = recoverFromStepErrorHandler;
+  }
+  onRootSuite(rootSuite) {
+    this._rootSuite = rootSuite;
+  }
+  onTestEnd(test, result) {
+    if (test.outcome() === "unexpected" && test.results.length > test.retries)
+      ++this._failureCount;
+  }
+  recoverFromStepError(stepId, error, resumeAfterStepError) {
+    if (!this._recoverFromStepErrorHandler) {
+      resumeAfterStepError({ stepId, status: "failed" });
+      return;
+    }
+    void this._recoverFromStepErrorHandler(stepId, error).then(resumeAfterStepError).catch(() => {
+    });
+  }
+  onWorkerError() {
+    this._hasWorkerErrors = true;
+  }
+  hasReachedMaxFailures() {
+    return this.maxFailures() > 0 && this._failureCount >= this.maxFailures();
+  }
+  hasWorkerErrors() {
+    return this._hasWorkerErrors;
+  }
+  result() {
+    return this._hasWorkerErrors || this.hasReachedMaxFailures() || this.hasFailedTests() || this._config.failOnFlakyTests && this.hasFlakyTests() ? "failed" : "passed";
+  }
+  hasFailedTests() {
+    return this._rootSuite?.allTests().some((test) => !test.ok());
+  }
+  hasFlakyTests() {
+    return this._rootSuite?.allTests().some((test) => test.outcome() === "flaky");
+  }
+  maxFailures() {
+    return this._config.config.maxFailures;
+  }
+}
+// Annotate the CommonJS export names for ESM import in node:
+0 && (module.exports = {
+  FailureTracker
+});