feat(all-users): add Last Action column showing most recent activity

src/components/Firebase/Firebase.tsx

@@ -4737,6 +4737,89 @@ class Firebase {
    * Gets all users from Firestore with relevant information for admin dashboard
    * @returns {Array} Array of user objects with id, name, email, role, status, and lastLogin
    */
+  /**
+   * Get last action date for all users by querying activity collections.
+   * Uses optimized approach: 5 total queries instead of per-user queries.
+   * @returns Map<userId, Date> - Last action date per user
+   */
+  getUsersLastAction = async (): Promise<Map<string, Date>> => {
+    const lastActionMap = new Map<string, Date>()
+
+    const updateIfNewer = (userId: string, date: Date | null) => {
+      if (!date || !userId) return
+      const current = lastActionMap.get(userId)
+      if (!current || date > current) {
+        lastActionMap.set(userId, date)
+      }
+    }
+
+    // Helper to extract userId from /user/ID format (used in observations)
+    const extractUserId = (ref: string): string => {
+      if (!ref) return ''
+      return ref.startsWith('/user/') ? ref.replace('/user/', '') : ref
+    }
+
+    // Query all 5 collections in parallel for better performance
+    const [observations, knowledgeChecks, conferencePlans, actionPlans, emails] = await Promise.all([
+      this.db.collection('observations').get(),
+      this.db.collection('knowledgeChecks').get(),
+      this.db.collection('conferencePlans').get(),
+      this.db.collection('actionPlans').get(),
+      this.db.collection('emails').get()
+    ])
+
+    // 1. Observations (largest collection - 20K+)
+    observations.docs.forEach(doc => {
+      const data = doc.data()
+      const userId = extractUserId(data.teacher)
+      const endDate = data.end?.toDate?.() || null
+      updateIfNewer(userId, endDate)
+    })
+
+    // 2. Knowledge Checks (6K+)
+    knowledgeChecks.docs.forEach(doc => {
+      const data = doc.data()
+      const userId = data.answeredBy
+      const timestamp = data.timestamp?.toDate?.() || null
+      updateIfNewer(userId, timestamp)
+    })
+
+    // 3. Conference Plans
+    conferencePlans.docs.forEach(doc => {
+      const data = doc.data()
+      const userId = data.teacher
+      const created = data.dateCreated?.toDate?.() || null
+      const modified = data.dateModified?.toDate?.() || null
+      updateIfNewer(userId, created)
+      updateIfNewer(userId, modified)
+    })
+
+    // 4. Action Plans
+    actionPlans.docs.forEach(doc => {
+      const data = doc.data()
+      const userId = data.teacher
+      const created = data.dateCreated?.toDate?.() || null
+      const modified = data.dateModified?.toDate?.() || null
+      updateIfNewer(userId, created)
+      updateIfNewer(userId, modified)
+    })
+
+    // 5. Emails (check both sender and recipient)
+    emails.docs.forEach(doc => {
+      const data = doc.data()
+      const senderId = data.user
+      const recipientId = data.recipientId
+      const created = data.dateCreated?.toDate?.() || null
+      const modified = data.dateModified?.toDate?.() || null
+      updateIfNewer(senderId, created)
+      updateIfNewer(senderId, modified)
+      updateIfNewer(recipientId, created)
+      updateIfNewer(recipientId, modified)
+    })
+
+    return lastActionMap
+  }
+
   getAllUsers = async () => {
     const result: Array<{
       id: string
@@ -4747,17 +4830,22 @@ class Firebase {
       program: string
       archived: boolean
       lastLogin: Date | null
+      lastAction: Date | null
     }> = []
 
-    // Fetch all programs to build a lookup map
-    const programsSnapshot = await this.db.collection('programs').get()
+    // Fetch programs, users, and last action data in parallel
+    const [programsSnapshot, usersSnapshot, lastActionMap] = await Promise.all([
+      this.db.collection('programs').get(),
+      this.db.collection('users').get(),
+      this.getUsersLastAction()
+    ])
+
+    // Build programs lookup map
     const programsMap = new Map<string, string>()
     programsSnapshot.docs.forEach(doc => {
       programsMap.set(doc.id, doc.data().name || '')
     })
 
-    const usersSnapshot = await this.db.collection('users').get()
-
     usersSnapshot.docs.forEach(doc => {
       const data = doc.data()
       // Get first program name from user's programs array
@@ -4800,6 +4888,7 @@ class Firebase {
         program: programName,
         archived: data.archived || false,
         lastLogin: data.lastLogin ? data.lastLogin.toDate() : null,
+        lastAction: lastActionMap.get(doc.id) || null,
       })
     })
 

src/components/UsersComponents/AllUsersTable.tsx

@@ -89,11 +89,12 @@ class AllUsersTable extends React.Component<Props, State> {
     if (statusFilter) users = users.filter(u => u.archived === (statusFilter === 'archived'))
 
     users.sort((a, b) => {
-      const aVal = sortField === 'lastLogin'
-        ? (a.lastLogin?.getTime() || 0)
+      const isDateField = sortField === 'lastLogin' || sortField === 'lastAction'
+      const aVal = isDateField
+        ? (a[sortField]?.getTime() || 0)
         : String(a[sortField] || '').toLowerCase()
-      const bVal = sortField === 'lastLogin'
-        ? (b.lastLogin?.getTime() || 0)
+      const bVal = isDateField
+        ? (b[sortField]?.getTime() || 0)
         : String(b[sortField] || '').toLowerCase()
       return sortDir === 'asc' ? (aVal > bVal ? 1 : -1) : (aVal < bVal ? 1 : -1)
     })
@@ -110,13 +111,14 @@ class AllUsersTable extends React.Component<Props, State> {
 
   handleExport = () => {
     const users = this.getFilteredUsers()
-    const headers = ['Last Name', 'First Name', 'Email', 'Role', 'Program', 'Status', 'Last Login']
+    const headers = ['Last Name', 'First Name', 'Email', 'Role', 'Program', 'Status', 'Last Login', 'Last Action']
     const escape = (val: string) => `"${(val || '').replace(/"/g, '""')}"`
     const rows = users.map(u => [
       escape(u.lastName), escape(u.firstName), escape(u.email),
       escape(this.formatRole(u.role)), escape(u.program || ''),
       escape(u.archived ? 'Archived' : 'Active'),
-      escape(this.formatDate(u.lastLogin))
+      escape(this.formatDate(u.lastLogin)),
+      escape(this.formatDate(u.lastAction))
     ].join(','))
     const csv = [headers.join(','), ...rows].join('\n')
     const blob = new Blob(['\ufeff' + csv], { type: 'text/csv;charset=utf-8;' })
@@ -179,12 +181,13 @@ class AllUsersTable extends React.Component<Props, State> {
                 <SortHeader field="program" label="Program" />
                 <SortHeader field="archived" label="Status" />
                 <SortHeader field="lastLogin" label="Last Login" />
+                <SortHeader field="lastAction" label="Last Action" />
                 <th style={{ padding: '4px 8px', textAlign: 'center', fontSize: '1.25rem', fontWeight: 500 }}><strong>Edit</strong></th>
               </tr>
             </thead>
             <tbody>
               {paginated.length === 0 ? (
-                <tr><TableCell colSpan={8} style={{ textAlign: 'center', padding: 40 }}>No users found</TableCell></tr>
+                <tr><TableCell colSpan={9} style={{ textAlign: 'center', padding: 40 }}>No users found</TableCell></tr>
               ) : paginated.map(user => (
                 <TableRow key={user.id}>
                   <TableCell>{user.lastName}</TableCell>
@@ -204,6 +207,7 @@ class AllUsersTable extends React.Component<Props, State> {
                     </Tooltip>
                   </TableCell>
                   <TableCell>{this.formatDate(user.lastLogin)}</TableCell>
+                  <TableCell>{this.formatDate(user.lastAction)}</TableCell>
                   <TableCell onClick={e => e.stopPropagation()} style={{ textAlign: 'center' }}>
                     <Tooltip title="Edit user">
                       <IconButton size="small" onClick={() => this.props.onUserClick?.(user)}>

src/constants/Types.tsx

@@ -233,6 +233,7 @@ export interface User {
     id: string
   }>,
   lastLogin?: Date,
+  lastAction?: Date,
   email?: string,
   school?: string,
   program?: string,