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/taskRunner.js

@@ -0,0 +1,127 @@
+"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 taskRunner_exports = {};
+__export(taskRunner_exports, {
+  TaskRunner: () => TaskRunner
+});
+module.exports = __toCommonJS(taskRunner_exports);
+var import_utils = require("playwright-core/lib/utils");
+var import_utils2 = require("playwright-core/lib/utils");
+var import_utilsBundle = require("playwright-core/lib/utilsBundle");
+var import_sigIntWatcher = require("./sigIntWatcher");
+var import_util = require("../util");
+class TaskRunner {
+  constructor(reporter, globalTimeoutForError) {
+    this._tasks = [];
+    this._hasErrors = false;
+    this._interrupted = false;
+    this._isTearDown = false;
+    this._reporter = reporter;
+    this._globalTimeoutForError = globalTimeoutForError;
+  }
+  addTask(task) {
+    this._tasks.push(task);
+  }
+  async run(context, deadline, cancelPromise) {
+    const { status, cleanup } = await this.runDeferCleanup(context, deadline, cancelPromise);
+    const teardownStatus = await cleanup();
+    return status === "passed" ? teardownStatus : status;
+  }
+  async runDeferCleanup(context, deadline, cancelPromise = new import_utils.ManualPromise()) {
+    const sigintWatcher = new import_sigIntWatcher.SigIntWatcher();
+    const timeoutWatcher = new TimeoutWatcher(deadline);
+    const teardownRunner = new TaskRunner(this._reporter, this._globalTimeoutForError);
+    teardownRunner._isTearDown = true;
+    let currentTaskName;
+    const taskLoop = async () => {
+      for (const task of this._tasks) {
+        currentTaskName = task.title;
+        if (this._interrupted)
+          break;
+        (0, import_utilsBundle.debug)("pw:test:task")(`"${task.title}" started`);
+        const errors = [];
+        const softErrors = [];
+        try {
+          teardownRunner._tasks.unshift({ title: `teardown for ${task.title}`, setup: task.teardown });
+          await task.setup?.(context, errors, softErrors);
+        } catch (e) {
+          (0, import_utilsBundle.debug)("pw:test:task")(`error in "${task.title}": `, e);
+          errors.push((0, import_util.serializeError)(e));
+        } finally {
+          for (const error of [...softErrors, ...errors])
+            this._reporter.onError?.(error);
+          if (errors.length) {
+            if (!this._isTearDown)
+              this._interrupted = true;
+            this._hasErrors = true;
+          }
+        }
+        (0, import_utilsBundle.debug)("pw:test:task")(`"${task.title}" finished`);
+      }
+    };
+    await Promise.race([
+      taskLoop(),
+      cancelPromise,
+      sigintWatcher.promise(),
+      timeoutWatcher.promise
+    ]);
+    sigintWatcher.disarm();
+    timeoutWatcher.disarm();
+    this._interrupted = true;
+    let status = "passed";
+    if (sigintWatcher.hadSignal() || cancelPromise?.isDone()) {
+      status = "interrupted";
+    } else if (timeoutWatcher.timedOut()) {
+      this._reporter.onError?.({ message: import_utils2.colors.red(`Timed out waiting ${this._globalTimeoutForError / 1e3}s for the ${currentTaskName} to run`) });
+      status = "timedout";
+    } else if (this._hasErrors) {
+      status = "failed";
+    }
+    cancelPromise?.resolve();
+    const cleanup = () => teardownRunner.runDeferCleanup(context, deadline).then((r) => r.status);
+    return { status, cleanup };
+  }
+}
+class TimeoutWatcher {
+  constructor(deadline) {
+    this._timedOut = false;
+    this.promise = new import_utils.ManualPromise();
+    if (!deadline)
+      return;
+    if (deadline - (0, import_utils.monotonicTime)() <= 0) {
+      this._timedOut = true;
+      this.promise.resolve();
+      return;
+    }
+    this._timer = setTimeout(() => {
+      this._timedOut = true;
+      this.promise.resolve();
+    }, deadline - (0, import_utils.monotonicTime)());
+  }
+  timedOut() {
+    return this._timedOut;
+  }
+  disarm() {
+    clearTimeout(this._timer);
+  }
+}
+// Annotate the CommonJS export names for ESM import in node:
+0 && (module.exports = {
+  TaskRunner
+});