fix: client file sharing access denied + task/project default tabs

- FileSharing: rootPath for clients strips /Clients/ prefix — API resolveClientPath expects /{company} not /Clients/{company}
- Tasks: default to To Do tab (not_started) instead of All Tasks
- Projects: default to Active tab instead of All Projects

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/pages/Tasks.jsx

@@ -73,7 +73,7 @@ function TasksStatsRow({ tasks = [] }) {
 function TasksPageShell({ statsTasks = [], projects = [], onAddProject = null, children }) {
   const [projSortKey, setProjSortKey] = useState('status');
   const [projSortDir, setProjSortDir] = useState('asc');
-  const [projTab, setProjTab] = useState('all');
+  const [projTab, setProjTab] = useState('active');
   const toggleProjSort = (col) => {
     if (projSortKey === col) setProjSortDir(d => d === 'asc' ? 'desc' : 'asc');
     else { setProjSortKey(col); setProjSortDir('asc'); }
@@ -193,7 +193,7 @@ export default function RequestsPage() {
   });
   const [error,    setError]    = useState('');
   const [loadError, setLoadError] = useState(false);
-  const [activeTab, setActiveTab] = useState('all');
+  const [activeTab, setActiveTab] = useState('not_started');
   const [filterCompany, setFilterCompany] = useState('');
   const [filterProject, setFilterProject] = useState('');
   const { sortKey, sortDir, toggle, sort } = useSortable('status', 'asc');