feat(webui): migrate pure UI ToolCall components and add Storybook stories

- Migrate ThinkToolCall, GenericToolCall, EditToolCall, WriteToolCall,
  SearchToolCall, UpdatedPlanToolCall, CheckboxDisplay to webui
- Add Storybook stories for all migrated components
- Add stories for shared components (ToolCallContainer, ToolCallCard,
  StatusIndicator, CodeBlock, LocationsList, CopyButton)
- Fix Storybook theme by reordering CSS imports and adding body color
- Update vscode-ide-companion to import ToolCall components from webui
- Keep ReadToolCall and ShellToolCall in vscode-ide-companion (VSCode deps)

packages/webui/src/utils/sessionGrouping.ts

@@ -0,0 +1,126 @@
+/**
+ * @license
+ * Copyright 2025 Qwen Team
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Session grouping utilities
+ * Functions for organizing sessions by date and formatting time ago
+ */
+
+/**
+ * Session group structure
+ */
+export interface SessionGroup {
+  /** Group label (e.g., "Today", "Yesterday") */
+  label: string;
+  /** Sessions in this group */
+  sessions: Array<Record<string, unknown>>;
+}
+
+/**
+ * Group sessions by date
+ *
+ * Categories:
+ * - Today: Sessions from today
+ * - Yesterday: Sessions from yesterday
+ * - This Week: Sessions from the last 7 days (excluding today/yesterday)
+ * - Older: Sessions older than a week
+ *
+ * @param sessions - Array of session objects (must have lastUpdated or startTime)
+ * @returns Array of grouped sessions, only includes non-empty groups
+ *
+ * @example
+ * ```ts
+ * const grouped = groupSessionsByDate(sessions);
+ * // [{ label: 'Today', sessions: [...] }, { label: 'Older', sessions: [...] }]
+ * ```
+ */
+export const groupSessionsByDate = (
+  sessions: Array<Record<string, unknown>>,
+): SessionGroup[] => {
+  const now = new Date();
+  const today = new Date(now.getFullYear(), now.getMonth(), now.getDate());
+  const yesterday = new Date(today);
+  yesterday.setDate(yesterday.getDate() - 1);
+
+  const groups: {
+    [key: string]: Array<Record<string, unknown>>;
+  } = {
+    Today: [],
+    Yesterday: [],
+    'This Week': [],
+    Older: [],
+  };
+
+  sessions.forEach((session) => {
+    const timestamp =
+      (session.lastUpdated as string) || (session.startTime as string) || '';
+    if (!timestamp) {
+      groups['Older'].push(session);
+      return;
+    }
+
+    const sessionDate = new Date(timestamp);
+    const sessionDay = new Date(
+      sessionDate.getFullYear(),
+      sessionDate.getMonth(),
+      sessionDate.getDate(),
+    );
+
+    if (sessionDay.getTime() === today.getTime()) {
+      groups['Today'].push(session);
+    } else if (sessionDay.getTime() === yesterday.getTime()) {
+      groups['Yesterday'].push(session);
+    } else if (sessionDay.getTime() > today.getTime() - 7 * 86400000) {
+      groups['This Week'].push(session);
+    } else {
+      groups['Older'].push(session);
+    }
+  });
+
+  return Object.entries(groups)
+    .filter(([, sessions]) => sessions.length > 0)
+    .map(([label, sessions]) => ({ label, sessions }));
+};
+
+/**
+ * Format timestamp as relative time string
+ *
+ * @param timestamp - ISO timestamp string
+ * @returns Formatted relative time (e.g., "now", "5m", "2h", "Yesterday", "3d", or date)
+ *
+ * @example
+ * ```ts
+ * getTimeAgo(new Date().toISOString()) // "now"
+ * getTimeAgo(thirtyMinutesAgo.toISOString()) // "30m"
+ * getTimeAgo(twoHoursAgo.toISOString()) // "2h"
+ * ```
+ */
+export const getTimeAgo = (timestamp: string): string => {
+  if (!timestamp) {
+    return '';
+  }
+  const now = new Date().getTime();
+  const then = new Date(timestamp).getTime();
+  const diffMs = now - then;
+  const diffMins = Math.floor(diffMs / 60000);
+  const diffHours = Math.floor(diffMs / 3600000);
+  const diffDays = Math.floor(diffMs / 86400000);
+
+  if (diffMins < 1) {
+    return 'now';
+  }
+  if (diffMins < 60) {
+    return `${diffMins}m`;
+  }
+  if (diffHours < 24) {
+    return `${diffHours}h`;
+  }
+  if (diffDays === 1) {
+    return 'Yesterday';
+  }
+  if (diffDays < 7) {
+    return `${diffDays}d`;
+  }
+  return new Date(timestamp).toLocaleDateString();
+};