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/testGroups.js

@@ -0,0 +1,117 @@
+"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 testGroups_exports = {};
+__export(testGroups_exports, {
+  createTestGroups: () => createTestGroups,
+  filterForShard: () => filterForShard
+});
+module.exports = __toCommonJS(testGroups_exports);
+function createTestGroups(projectSuite, expectedParallelism) {
+  const groups = /* @__PURE__ */ new Map();
+  const createGroup = (test) => {
+    return {
+      workerHash: test._workerHash,
+      requireFile: test._requireFile,
+      repeatEachIndex: test.repeatEachIndex,
+      projectId: test._projectId,
+      tests: []
+    };
+  };
+  for (const test of projectSuite.allTests()) {
+    let withWorkerHash = groups.get(test._workerHash);
+    if (!withWorkerHash) {
+      withWorkerHash = /* @__PURE__ */ new Map();
+      groups.set(test._workerHash, withWorkerHash);
+    }
+    let withRequireFile = withWorkerHash.get(test._requireFile);
+    if (!withRequireFile) {
+      withRequireFile = {
+        general: createGroup(test),
+        parallel: /* @__PURE__ */ new Map(),
+        parallelWithHooks: createGroup(test)
+      };
+      withWorkerHash.set(test._requireFile, withRequireFile);
+    }
+    let insideParallel = false;
+    let outerMostSequentialSuite;
+    let hasAllHooks = false;
+    for (let parent = test.parent; parent; parent = parent.parent) {
+      if (parent._parallelMode === "serial" || parent._parallelMode === "default")
+        outerMostSequentialSuite = parent;
+      insideParallel = insideParallel || parent._parallelMode === "parallel";
+      hasAllHooks = hasAllHooks || parent._hooks.some((hook) => hook.type === "beforeAll" || hook.type === "afterAll");
+    }
+    if (insideParallel) {
+      if (hasAllHooks && !outerMostSequentialSuite) {
+        withRequireFile.parallelWithHooks.tests.push(test);
+      } else {
+        const key = outerMostSequentialSuite || test;
+        let group = withRequireFile.parallel.get(key);
+        if (!group) {
+          group = createGroup(test);
+          withRequireFile.parallel.set(key, group);
+        }
+        group.tests.push(test);
+      }
+    } else {
+      withRequireFile.general.tests.push(test);
+    }
+  }
+  const result = [];
+  for (const withWorkerHash of groups.values()) {
+    for (const withRequireFile of withWorkerHash.values()) {
+      if (withRequireFile.general.tests.length)
+        result.push(withRequireFile.general);
+      result.push(...withRequireFile.parallel.values());
+      const parallelWithHooksGroupSize = Math.ceil(withRequireFile.parallelWithHooks.tests.length / expectedParallelism);
+      let lastGroup;
+      for (const test of withRequireFile.parallelWithHooks.tests) {
+        if (!lastGroup || lastGroup.tests.length >= parallelWithHooksGroupSize) {
+          lastGroup = createGroup(test);
+          result.push(lastGroup);
+        }
+        lastGroup.tests.push(test);
+      }
+    }
+  }
+  return result;
+}
+function filterForShard(shard, testGroups) {
+  let shardableTotal = 0;
+  for (const group of testGroups)
+    shardableTotal += group.tests.length;
+  const shardSize = Math.floor(shardableTotal / shard.total);
+  const extraOne = shardableTotal - shardSize * shard.total;
+  const currentShard = shard.current - 1;
+  const from = shardSize * currentShard + Math.min(extraOne, currentShard);
+  const to = from + shardSize + (currentShard < extraOne ? 1 : 0);
+  let current = 0;
+  const result = /* @__PURE__ */ new Set();
+  for (const group of testGroups) {
+    if (current >= from && current < to)
+      result.add(group);
+    current += group.tests.length;
+  }
+  return result;
+}
+// Annotate the CommonJS export names for ESM import in node:
+0 && (module.exports = {
+  createTestGroups,
+  filterForShard
+});