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/vcs.js

@@ -0,0 +1,72 @@
+"use strict";
+var __create = Object.create;
+var __defProp = Object.defineProperty;
+var __getOwnPropDesc = Object.getOwnPropertyDescriptor;
+var __getOwnPropNames = Object.getOwnPropertyNames;
+var __getProtoOf = Object.getPrototypeOf;
+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 __toESM = (mod, isNodeMode, target) => (target = mod != null ? __create(__getProtoOf(mod)) : {}, __copyProps(
+  // If the importer is in node compatibility mode or this is not an ESM
+  // file that has been converted to a CommonJS file using a Babel-
+  // compatible transform (i.e. "__esModule" has not been set), then set
+  // "default" to the CommonJS "module.exports" for node compatibility.
+  isNodeMode || !mod || !mod.__esModule ? __defProp(target, "default", { value: mod, enumerable: true }) : target,
+  mod
+));
+var __toCommonJS = (mod) => __copyProps(__defProp({}, "__esModule", { value: true }), mod);
+var vcs_exports = {};
+__export(vcs_exports, {
+  detectChangedTestFiles: () => detectChangedTestFiles
+});
+module.exports = __toCommonJS(vcs_exports);
+var import_child_process = __toESM(require("child_process"));
+var import_path = __toESM(require("path"));
+var import_compilationCache = require("../transform/compilationCache");
+async function detectChangedTestFiles(baseCommit, configDir) {
+  function gitFileList(command) {
+    try {
+      return import_child_process.default.execSync(
+        `git ${command}`,
+        { encoding: "utf-8", stdio: "pipe", cwd: configDir }
+      ).split("\n").filter(Boolean);
+    } catch (_error) {
+      const error = _error;
+      const unknownRevision = error.output.some((line) => line?.includes("unknown revision"));
+      if (unknownRevision) {
+        const isShallowClone = import_child_process.default.execSync("git rev-parse --is-shallow-repository", { encoding: "utf-8", stdio: "pipe", cwd: configDir }).trim() === "true";
+        if (isShallowClone) {
+          throw new Error([
+            `The repository is a shallow clone and does not have '${baseCommit}' available locally.`,
+            `Note that GitHub Actions checkout is shallow by default: https://github.com/actions/checkout`
+          ].join("\n"));
+        }
+      }
+      throw new Error([
+        `Cannot detect changed files for --only-changed mode:`,
+        `git ${command}`,
+        "",
+        ...error.output
+      ].join("\n"));
+    }
+  }
+  const untrackedFiles = gitFileList(`ls-files --others --exclude-standard`).map((file) => import_path.default.join(configDir, file));
+  const [gitRoot] = gitFileList("rev-parse --show-toplevel");
+  const trackedFilesWithChanges = gitFileList(`diff ${baseCommit} --name-only`).map((file) => import_path.default.join(gitRoot, file));
+  return new Set((0, import_compilationCache.affectedTestFiles)([...untrackedFiles, ...trackedFilesWithChanges]));
+}
+// Annotate the CommonJS export names for ESM import in node:
+0 && (module.exports = {
+  detectChangedTestFiles
+});