feat: v2.5.4 — Query Explorer folded into Sessions, Windows picker and paths

- Sessions page tabs: Sessions · Events · Agents. QueryExplorer.tsx became
  AgentsTable.tsx (agents only — sessions and events already had tabs);
  /query redirects to /sessions?view=agents and leaves the sidebar.
  GET /api/query is unchanged and still answers all three entities.
- Windows picker opens in front: -EncodedCommand script spends the hidden
  first ShowWindow that windowsHide gives the process, then brings the TopMost
  owner forward via AttachThreadInput (v2.5.3's owner was itself hidden).
- Session page Resume/Fork/Open pane: owningLane and sessionWorktreeName
  match Windows folders (either separator), with a test.

client/src/App.tsx

@@ -85,9 +85,6 @@ const SessionDetail = lazy(() =>
 const SnapshotView = lazy(() =>
   import("./pages/SnapshotView").then((m) => ({ default: m.SnapshotView }))
 );
-const QueryExplorer = lazy(() =>
-  import("./pages/QueryExplorer").then((m) => ({ default: m.QueryExplorer }))
-);
 
 function PageFallback() {
   const { t } = useTranslation();
@@ -172,14 +169,7 @@ export default function App() {
                 </Page>
               }
             />
-            <Route
-              path="query"
-              element={
-                <Page>
-                  <QueryExplorer />
-                </Page>
-              }
-            />
+            <Route path="query" element={<Navigate to="/sessions?view=agents" replace />} />
             <Route path="activity" element={<Navigate to="/sessions?view=events" replace />} />
             <Route
               path="workflows"