diff --git a/src/pages/TaskDetail.jsx b/src/pages/TaskDetail.jsx
index 56723dc..bed9159 100644
--- a/src/pages/TaskDetail.jsx
+++ b/src/pages/TaskDetail.jsx
@@ -10,6 +10,7 @@ import { logActivity } from '../lib/activityLog';
 import JSZip from 'jszip';
 import { popupOverlayStyle, popupSurfaceStyle } from '../lib/popupStyles';
 import { useLiveRefresh } from '../hooks/useLiveRefresh';
+import { useActionLock } from '../hooks/useActionLock';
 import FileAttachment from '../components/FileAttachment';
 import { sendTaskStatusUpdate } from '../lib/taskNotifications';
 import { encodeRejectedNote, parseRejectedNote, isReviewShadowSubmission, REVIEW_SHADOW_PREFIX, getVisibleTaskSubmissions, getTaskDerivedState } from '../lib/taskVersions';
@@ -254,6 +255,7 @@ export default function TaskDetail() {
   const [loading, setLoading] = useState(true);
   const [activeTab, setActiveTab] = useState('Overview');
   const [statusSaving, setStatusSaving] = useState(false);
+  const guard = useActionLock();
   const [downloading, setDownloading] = useState('');
   const [revisionModal, setRevisionModal] = useState(false);
   const [revisionForm, setRevisionForm] = useState({ description: '', deadline: '' });
@@ -388,7 +390,7 @@ export default function TaskDetail() {
 
   const log = (action) => logActivity({ actorId: currentUser.id, actorName: currentUser.name, action, taskId: id, taskTitle: task?.title, projectId: task?.project?.id, projectName: task?.project?.name });
 
-  const updateStatus = async (newStatus, extra = {}, action = null) => {
+  const updateStatus = guard('status', async (newStatus, extra = {}, action = null) => {
     setStatusSaving(true);
     const prevTask = task;
     setTask(t => ({ ...t, status: newStatus, ...extra }));
@@ -409,7 +411,7 @@ export default function TaskDetail() {
     } finally {
       setStatusSaving(false);
     }
-  };
+  });
 
   const handleStart = () => updateStatus('in_progress', { assigned_to: currentUser.id, assigned_name: currentUser.name }, 'task_started');
   const handleOnHold = async () => {
@@ -428,7 +430,7 @@ export default function TaskDetail() {
   const handleResume = () => updateStatus('in_progress', {}, 'task_resumed');
   const handleSendToReview = () => { setReviewFiles([]); setReviewNotes(''); setReviewModal(true); };
   const handleRemoveFromReview = () => updateStatus('in_progress', {}, 'task_resumed');
-  const handleConfirmReview = async () => {
+  const handleConfirmReview = guard('review', async () => {
     setReviewSaving(true);
     try {
       const targetVersion = task.current_version || 0;
@@ -505,8 +507,8 @@ export default function TaskDetail() {
     } finally {
       setReviewSaving(false);
     }
-  };
-  const handleClientApprove = async () => {
+  });
+  const handleClientApprove = guard('approve', async () => {
     await updateStatus('client_approved', { completed_at: new Date().toISOString() }, 'task_approved');
     sendTaskStatusUpdate({
       ...notificationBase,
@@ -518,14 +520,14 @@ export default function TaskDetail() {
       includeAssigned: true,
       includeClient: true,
     }).catch(() => {});
-  };
+  });
   const handleClientReject = () => { setRejectNote(''); setRejectModal(true); };
-  const handleSubmitReject = async () => {
+  const handleSubmitReject = guard('reject', async () => {
     if (!rejectNote.trim()) return;
     setRejectSaving(true);
     try {
       const rejectedVersion = task.current_version || 0;
-      const { data: rejectedNoteSubmission } = await supabase
+      const { data: rejectedNoteSubmission, error: rejectNoteError } = await supabase
         .from('submissions')
         .insert({
           task_id: id,
@@ -538,7 +540,15 @@ export default function TaskDetail() {
         })
         .select()
         .single();
-      if (rejectedNoteSubmission) setSubmissions(prev => [...prev, rejectedNoteSubmission]);
+      // The rejection reason lives only in this submission row. If it didn't
+      // save, do NOT flip status or log the rejection — otherwise the task
+      // shows as "rejected" with no reason. Surface the error and bail.
+      if (rejectNoteError || !rejectedNoteSubmission) {
+        console.error('Reject note save failed:', rejectNoteError);
+        window.alert(rejectNoteError?.message || 'Failed to save the rejection reason. The task was not rejected — please try again.');
+        return;
+      }
+      setSubmissions(prev => [...prev, rejectedNoteSubmission]);
       await updateStatus('in_progress', {}, 'revision_requested');
       sendTaskStatusUpdate({
         ...notificationBase,
@@ -555,10 +565,10 @@ export default function TaskDetail() {
     } finally {
       setRejectSaving(false);
     }
-  };
+  });
   const handleRelease = () => updateStatus('not_started', { assigned_to: null, assigned_name: null }, 'task_released');
 
-  const handleSubmitRevision = async () => {
+  const handleSubmitRevision = guard('revision', async () => {
     setRevisionSaving(true);
     const baseline = Math.max(task.current_version || 0, ...submissions.map(s => s.version_number || 0));
     const newVersion = baseline + 1;
@@ -602,9 +612,9 @@ export default function TaskDetail() {
     setRevisionForm({ description: '', deadline: '' });
     setRevisionFiles([]);
     setRevisionSaving(false);
-  };
+  });
 
-  const handleSubmitAmendment = async () => {
+  const handleSubmitAmendment = guard('amend', async () => {
     if (!amendForm.description.trim()) return;
     setAmendSaving(true);
     setAmendModal(false);
@@ -638,16 +648,16 @@ export default function TaskDetail() {
     setAmendForm({ description: '' });
     setAmendFiles([]);
     setAmendSaving(false);
-  };
+  });
 
-  const handlePostComment = async () => {
+  const handlePostComment = guard('comment', async () => {
     if (!commentBody.trim()) return;
     setCommentSaving(true);
     const { data } = await supabase.from('task_comments').insert({ task_id: id, author_id: currentUser.id, author_name: currentUser.name, body: commentBody.trim() }).select().single();
     if (data) setComments(prev => [...prev, data]);
     setCommentBody('');
     setCommentSaving(false);
-  };
+  });
 
   const handleDeleteComment = async (commentId) => {
     await supabase.from('task_comments').delete().eq('id', commentId);
diff --git a/supabase/migrations/20260623120000_auto_complete_project_on_tasks_done.sql b/supabase/migrations/20260623120000_auto_complete_project_on_tasks_done.sql
new file mode 100644
index 0000000..deb2b49
--- /dev/null
+++ b/supabase/migrations/20260623120000_auto_complete_project_on_tasks_done.sql
@@ -0,0 +1,95 @@
+-- Auto-complete a project when all its tasks are done, and reopen it when they are not.
+--
+-- Context: projects.status was only ever set to 'active' on insert and never
+-- transitioned by application code. The 100% progress bar in the UI is derived
+-- purely from task statuses (done / total) and was never written back to
+-- projects.status, so projects sat at 'active' forever once all tasks were done.
+-- This trigger keeps projects.status in sync with their tasks.
+--
+-- "Done" mirrors the UI's doneStatuses set. In the live DB the terminal task
+-- status is 'client_approved'; 'invoiced'/'paid' are included for parity with the
+-- app in case those are ever used as task statuses.
+--
+-- Only flips between 'active' and 'completed'. Any other status (e.g. a future
+-- manual 'cancelled') is left untouched.
+
+create or replace function public.recompute_project_status(p_project_id uuid)
+returns void as $$
+declare
+  total_count integer;
+  done_count  integer;
+begin
+  if p_project_id is null then
+    return;
+  end if;
+
+  select
+    count(*),
+    count(*) filter (where status in ('client_approved', 'invoiced', 'paid'))
+  into total_count, done_count
+  from public.tasks
+  where project_id = p_project_id;
+
+  if total_count > 0 and done_count = total_count then
+    update public.projects
+       set status = 'completed'
+     where id = p_project_id
+       and status = 'active';
+  else
+    update public.projects
+       set status = 'active'
+     where id = p_project_id
+       and status = 'completed';
+  end if;
+end;
+$$ language plpgsql security definer
+set search_path = public;
+
+create or replace function public.sync_project_status_from_task()
+returns trigger as $$
+begin
+  if tg_op = 'DELETE' then
+    perform public.recompute_project_status(old.project_id);
+    return old;
+  end if;
+
+  -- INSERT or UPDATE
+  perform public.recompute_project_status(new.project_id);
+
+  -- A task moved between projects: also recompute the old project.
+  if tg_op = 'UPDATE' and new.project_id is distinct from old.project_id then
+    perform public.recompute_project_status(old.project_id);
+  end if;
+
+  return new;
+end;
+$$ language plpgsql security definer
+set search_path = public;
+
+drop trigger if exists sync_project_status on public.tasks;
+create trigger sync_project_status
+  after insert or update or delete on public.tasks
+  for each row execute function public.sync_project_status_from_task();
+
+-- Backfill existing data to the correct state.
+update public.projects p
+   set status = 'completed'
+ where p.status = 'active'
+   and exists (select 1 from public.tasks t where t.project_id = p.id)
+   and not exists (
+     select 1 from public.tasks t
+      where t.project_id = p.id
+        and t.status not in ('client_approved', 'invoiced', 'paid')
+   );
+
+update public.projects p
+   set status = 'active'
+ where p.status = 'completed'
+   and (
+     not exists (select 1 from public.tasks t where t.project_id = p.id)
+     or exists (
+       select 1 from public.tasks t
+        where t.project_id = p.id
+          and t.status not in ('client_approved', 'invoiced', 'paid')
+     )
+   );