fix(ui): collapse session lists and scope selection controls to panels

frontend/src/shell/AppShell.tsx

@@ -256,7 +256,7 @@ export function AppShell({ canLogout }: AppShellProps) {
   const contextLocked = interactionBusy || creatingSession || administrationBusy
     || preprocessingQuery.data?.state === "running";
   const [adminNavigationValue, setAdminNavigationValue] = useState<string[]>([]);
-  const [activeOpen, setActiveOpen] = useState(true);
+  const [activeOpen, setActiveOpen] = useState(false);
   const [archiveOpen, setArchiveOpen] = useState(false);
   const [renameTarget, setRenameTarget] = useState<SessionSummary | null>(null);
   const [deleteTargets, setDeleteTargets] = useState<SessionSummary[]>([]);
@@ -326,8 +326,39 @@ export function AppShell({ canLogout }: AppShellProps) {
     });
   }
 
-  function toggleAllSessions(selected: boolean) {
-    setSelectedSessionIds(selected ? new Set(sessions.map((session) => session.id)) : new Set());
+  function sessionSelectionControls(list: SessionSummary[]) {
+    if (list.length === 0) return null;
+    const selected = list.filter((session) => selectedSessionIds.has(session.id));
+    return (
+      <div className="flex items-center justify-between gap-2 px-2 pb-2">
+        <label className="flex cursor-pointer items-center gap-2 text-xs font-medium text-muted-foreground hover:text-foreground">
+          <Checkbox
+            checked={selected.length === list.length}
+            indeterminate={selected.length > 0 && selected.length < list.length}
+            onCheckedChange={(checked) => setSelectedSessionIds((current) => {
+              const next = new Set(current);
+              for (const session of list) {
+                if (checked) next.add(session.id);
+                else next.delete(session.id);
+              }
+              return next;
+            })}
+          />
+          <span>{t("Select all")}</span>
+        </label>
+        {selected.length > 0 && (
+          <Button
+            variant="destructive"
+            size="xs"
+            aria-label={t("Delete {count} selected sessions", { count: selected.length })}
+            onClick={() => requestDelete(selected)}
+          >
+            <Trash2 />
+            {t("Delete ({count})", { count: selected.length })}
+          </Button>
+        )}
+      </div>
+    );
   }
 
   function handleSessionScopeTabKeyDown(
@@ -1124,42 +1155,11 @@ export function AppShell({ canLogout }: AppShellProps) {
           className="flex min-h-0 flex-1 flex-col"
         >
           {canReadAllSessions && showingAllSessions && (
-            <p className="mx-4 mb-2 mt-2 text-xs font-medium text-muted-foreground">
+            <p className="sr-only">
               {t("Administrator view: all sessions")}
             </p>
           )}
 
-          {/* L1 — rail title */}
-          <div className="px-4 pb-1.5 pt-1">
-            <span className="text-sm font-semibold text-foreground">
-              {t("Sessions")}
-            </span>
-          </div>
-
-          <div className="flex items-center justify-between px-4 pb-2">
-            <label className="flex cursor-pointer items-center gap-2 text-xs font-medium text-muted-foreground hover:text-foreground">
-              <Checkbox
-                checked={allSessionsSelected}
-                aria-label={t("Select all sessions")}
-                disabled={sessions.length === 0}
-                onCheckedChange={(selected) => toggleAllSessions(selected === true)}
-              />
-              <span>{t("Select all")}</span>
-            </label>
-            {selectedSessions.length > 0 && (
-              <Button
-                variant="destructive"
-                size="xs"
-                aria-label={t("Delete {count} selected sessions", { count: selectedSessions.length })}
-                onClick={() => {
-                  requestDelete(selectedSessions);
-                }}
-              >
-                <Trash2 />
-                {t("Delete ({count})", { count: selectedSessions.length })}
-              </Button>
-            )}
-          </div>
           <Accordion.Root multiple
             value={[...(activeOpen ? ["active"] : []), ...(archiveOpen ? ["archive"] : [])]}
             onValueChange={value => { setActiveOpen(value.includes("active")); setArchiveOpen(value.includes("archive")); }}
@@ -1172,6 +1172,7 @@ export function AppShell({ canLogout }: AppShellProps) {
               </Accordion.Trigger>
             </Accordion.Header>
             <Accordion.Panel className="thot-session-accordion__panel" tabIndex={0}>
+            {sessionSelectionControls(activeList)}
             <div className="flex flex-col gap-3 pb-2">
               {groups.map((g) => (
                 <div key={g}>
@@ -1233,6 +1234,7 @@ export function AppShell({ canLogout }: AppShellProps) {
               </Accordion.Trigger>
             </Accordion.Header>
             <Accordion.Panel className="thot-session-accordion__panel" tabIndex={0}>
+            {sessionSelectionControls(archivedList)}
             <NavSessions
               sessions={archivedList}
               activeSessionId={activeSessionId}