chore(frontend): real ESLint instead of a placeholder; fix hook order (FLAW-19)

eslint.config.js with the recommended JS/TypeScript rules and the React
hooks rules; npm run lint runs ESLint and is part of the image build.
Errors fail the build, the 24 exhaustive-deps findings stay warnings.

It found two real bugs: TaskDetailModal and ManageColumnsModal called
their hooks after 'if (!isOpen) return null', so the hook count changed
whenever the dialog opened or closed. Both are now a thin wrapper plus a
content component. Also removes unused imports and dead code (old task
list share handlers, an unused realtime status, an unused rollup).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/features/triage/TasksView.tsx

@@ -15,19 +15,18 @@ import {
   Layers,
   Users,
   CheckSquare,
-  User as UserIcon,
+  User as 
   Lock,
   Hash,
   AlertTriangle,
   Flame,
   Settings,
-  ChevronDown,
   Folder,
   Filter,
   Webhook,
   Repeat,
 } from 'lucide-react';
-import { TaskList, Thought, SubTask, Team, User, TaskListShare, TaskListMember, KanbanColumn, PriorityLevel, Recurrence, RECURRENCE_LABELS } from '../../lib/types';
+import { TaskList, Thought, SubTask, Team, User, TaskListMember, KanbanColumn, PriorityLevel, Recurrence, RECURRENCE_LABELS } from '../../lib/types';
 import { formatDue, isDueToday, isOverdue, localDay, splitDue } from '../../lib/due';
 import { api, triggerHaptic } from '../../lib/api';
 import { UnifiedShareModal } from '../../components/UnifiedShareModal';
@@ -92,10 +91,6 @@ export const TasksView: React.FC<TasksViewProps> = ({
   // Share TaskList modal state
   const [showShareListModal, setShowShareListModal] = useState(false);
   const [sharingTaskList, setSharingTaskList] = useState<TaskList | null>(null);
-  const [addShareType, setAddShareType] = useState<'team' | 'user'>('team');
-  const [selectedShareTargetId, setSelectedShareTargetId] = useState('');
-  const [selectedShareUser, setSelectedShareUser] = useState<User | null>(null);
-  const [shareLoading, setShareLoading] = useState(false);
 
   // Detail modal state
   const [detailTaskId, setDetailTaskId] = useState<string | null>(null);
@@ -854,8 +849,6 @@ export const TasksView: React.FC<TasksViewProps> = ({
 
   const handleOpenShareModal = async (tl: TaskList) => {
     setSharingTaskList(tl);
-    setSelectedShareTargetId('');
-    setSelectedShareUser(null);
     setShowShareListModal(true);
     try {
       const [freshTeams, freshUsers, freshShares] = await Promise.all([
@@ -871,60 +864,6 @@ export const TasksView: React.FC<TasksViewProps> = ({
     }
   };
 
-  const handleAddShare = async () => {
-    if (!sharingTaskList) return;
-    const targetId = addShareType === 'team' ? selectedShareTargetId : selectedShareUser?.id;
-    if (!targetId) return;
-    setShareLoading(true);
-    triggerHaptic(15);
-    try {
-      await api.addTaskListShare(sharingTaskList.id, {
-        targetType: addShareType,
-        targetId: targetId,
-      });
-      const [freshLists, freshShares] = await Promise.all([
-        api.getTaskLists(),
-        api.getTaskListShares(sharingTaskList.id).catch(() => []),
-      ]);
-      setTaskLists(freshLists);
-      const updated = freshLists.find((l) => l.id === sharingTaskList.id);
-      if (updated) {
-        setSharingTaskList({ ...updated, shares: freshShares });
-      }
-      setSelectedShareTargetId('');
-      setSelectedShareUser(null);
-      await loadData();
-    } catch (err: any) {
-      alert(err.message || 'Fehler beim Hinzufügen der Freigabe');
-    } finally {
-      setShareLoading(false);
-    }
-  };
-
-  const handleRemoveShare = async (shareId: string) => {
-    if (!sharingTaskList) return;
-    if (!window.confirm('Freigabe wirklich aufheben?')) return;
-    setShareLoading(true);
-    triggerHaptic(15);
-    try {
-      await api.removeTaskListShare(sharingTaskList.id, shareId);
-      const [freshLists, freshShares] = await Promise.all([
-        api.getTaskLists(),
-        api.getTaskListShares(sharingTaskList.id).catch(() => []),
-      ]);
-      setTaskLists(freshLists);
-      const updated = freshLists.find((l) => l.id === sharingTaskList.id);
-      if (updated) {
-        setSharingTaskList({ ...updated, shares: freshShares });
-      }
-      await loadData();
-    } catch (err: any) {
-      alert(err.message || 'Fehler beim Entfernen der Freigabe');
-    } finally {
-      setShareLoading(false);
-    }
-  };
-
   const handleSaveColumns = async (newColumns: KanbanColumn[]) => {
     triggerHaptic(15);
     if (currentSelectedList && selectedListId !== 'all') {