batch4.1-5.1: dedup audit, archive 400 fix, sidebar Delete, landing-page enrichment, auto-name tool-call fix

- Fastify global empty-JSON-body parser fixes archive/unarchive/stop 400s
- Removed redundant local sessionEvents.emit at all 5+2 sites with server-side WS publishers; added dedupe guards in useSidebar/Workspace/Project handlers
- Sidebar session right-click adds Delete (destructive) with confirm Dialog
- Session.tsx navigates away on session_deleted/session_archived for the active session
- SessionLandingPage chat rows show message_count, effective_context_tokens, last_message_preview via LATERAL joins on GET /api/sessions/:id/chats
- Workspace.tsx pane drag-to-reorder using native HTML5 events (no new deps)
- CompactCard: Copy toast, Send-to-chat with target chat name, empty-state in share popover, Re-run button
- auto_name.ts: filter count gate and assistant-fetch by content <> '' so tool-call assistant rows don't trip the once-and-only-once guard
- Adds CLAUDE.md and apps/web/src/lib/format.ts

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/src/components/ProjectSidebar.tsx

@@ -16,6 +16,13 @@ import {
   ContextMenuSeparator,
   ContextMenuTrigger,
 } from '@/components/ui/context-menu';
+import {
+  Dialog,
+  DialogContent,
+  DialogHeader,
+  DialogTitle,
+  DialogDescription,
+} from '@/components/ui/dialog';
 import { AddProjectModal } from './AddProjectModal';
 import { api } from '@/api/client';
 import { sessionEvents } from '@/hooks/sessionEvents';
@@ -100,6 +107,7 @@ export function ProjectSidebar() {
   const [expanded, setExpanded] = useState<Set<string>>(() => readExpanded());
   const [renamingSession, setRenamingSession] = useState<string | null>(null);
   const [renameValue, setRenameValue] = useState('');
+  const [deleteConfirm, setDeleteConfirm] = useState<{ id: string; name: string } | null>(null);
   const navigate = useNavigate();
   const location = useLocation();
   const lastToastedError = useRef<string | null>(null);
@@ -135,7 +143,7 @@ export function ProjectSidebar() {
   async function handleRemove(id: string) {
     try {
       await api.projects.remove(id);
-      sessionEvents.emit({ type: 'project_deleted', project_id: id });
+      // Server publishes project_deleted via WS; useUserEvents delivers it.
       navigate('/');
     } catch (err) {
       toast.error(err instanceof Error ? err.message : 'failed to remove project');
@@ -145,13 +153,23 @@ export function ProjectSidebar() {
   async function handleArchiveSession(sessionId: string, projectId: string) {
     try {
       await api.sessions.archive(sessionId);
-      sessionEvents.emit({ type: 'session_archived', session_id: sessionId, project_id: projectId });
+      // Server publishes session_archived via WS; useUserEvents delivers it.
       if (activeSession === sessionId) navigate(`/project/${projectId}`);
     } catch (err) {
       toast.error(err instanceof Error ? err.message : 'failed to archive session');
     }
   }
 
+  async function handleDeleteSession(sessionId: string, projectId: string) {
+    try {
+      await api.sessions.remove(sessionId);
+      // Server publishes session_deleted via WS; useUserEvents delivers it.
+      if (activeSession === sessionId) navigate(`/project/${projectId}`);
+    } catch (err) {
+      toast.error(err instanceof Error ? err.message : 'failed to delete session');
+    }
+  }
+
   async function handleRenameSession(sessionId: string) {
     const trimmed = renameValue.trim();
     setRenamingSession(null);
@@ -293,10 +311,16 @@ export function ProjectSidebar() {
                           }}>
                             Rename
                           </ContextMenuItem>
-                          <ContextMenuSeparator />
                           <ContextMenuItem onSelect={() => void handleArchiveSession(s.id, p.id)}>
                             Archive
                           </ContextMenuItem>
+                          <ContextMenuSeparator />
+                          <ContextMenuItem
+                            variant="destructive"
+                            onSelect={() => setDeleteConfirm({ id: s.id, name: s.name })}
+                          >
+                            Delete
+                          </ContextMenuItem>
                         </ContextMenuContent>
                       </ContextMenu>
                     ))}
@@ -316,6 +340,36 @@ export function ProjectSidebar() {
       </nav>
 
       <AddProjectModal open={addOpen} onOpenChange={setAddOpen} onAdded={() => {}} />
+
+      <Dialog open={deleteConfirm !== null} onOpenChange={(open) => { if (!open) setDeleteConfirm(null); }}>
+        <DialogContent>
+          <DialogHeader>
+            <DialogTitle>Delete session?</DialogTitle>
+            <DialogDescription>
+              This will permanently delete {deleteConfirm ? `"${deleteConfirm.name}"` : 'this session'} and all its chats and messages. This cannot be undone.
+            </DialogDescription>
+          </DialogHeader>
+          <div className="flex gap-2 justify-end pt-2">
+            <Button variant="outline" onClick={() => setDeleteConfirm(null)}>
+              Cancel
+            </Button>
+            <Button
+              variant="destructive"
+              onClick={() => {
+                if (deleteConfirm) {
+                  const projectId = projects.find((p) =>
+                    p.recent_sessions.some((s) => s.id === deleteConfirm.id)
+                  )?.id;
+                  if (projectId) void handleDeleteSession(deleteConfirm.id, projectId);
+                }
+                setDeleteConfirm(null);
+              }}
+            >
+              Delete
+            </Button>
+          </div>
+        </DialogContent>
+      </Dialog>
     </aside>
   );
 }