feat(desktop): drag sidebar rows by the title, not just the grabber

The grabber in the lead column was the only way to reorder a session or a
project, and it only appears on hover — a 14px target for the whole gesture.
The row's title is the obvious thing to grab, so put the sortable listeners
on the row shell.

For a session that means two drags share one press, since the title already
starts the drag into the layout. They need no arbitration: each declines
outside its own region. Over the sidebar only the reorder has a target (the
session drop denies — side chrome hosts no main tile); over the tree only the
session drop does (no sortable row there). Whichever the release lands on is
the one that commits.

Rows exclude their own controls through one data-row-actions selector, now
owned by SidebarRowShell instead of restated per row.

apps/desktop/src/app/chat/sidebar/chrome.tsx

@@ -55,7 +55,9 @@ export function SidebarDateDivider({ className, label, ...props }: React.Compone
   )
 }
 
-/** Outer grid — sole owner of row height. */
+/** Outer grid — sole owner of row height. The trailing `actions` slot is
+ *  marked `data-row-actions` so a row-wide drag gesture can exclude it with
+ *  one selector: it holds real controls, never grab surface. */
 export function SidebarRowShell({
   actions,
   children,
@@ -65,7 +67,11 @@ export function SidebarRowShell({
   return (
     <div className={cn(rowMinH, 'grid grid-cols-[minmax(0,1fr)_auto] items-stretch rounded-md', className)} {...props}>
       {children}
-      {actions ? <div className="flex shrink-0 items-center self-center">{actions}</div> : null}
+      {actions ? (
+        <div className="flex shrink-0 items-center self-center" data-row-actions>
+          {actions}
+        </div>
+      ) : null}
     </div>
   )
 }

apps/desktop/src/app/chat/sidebar/projects/overview-row.tsx

@@ -125,6 +125,18 @@ export function ProjectOverviewRow({
         </>
       }
       className={cn('group/workspace', dragging && 'cursor-grabbing bg-(--ui-sidebar-surface-background)')}
+      // The label is grab surface too, not just the lead's grabber — same
+      // listeners, minus the controls that keep their own gestures. A project
+      // row has no rival drag (its title navigates on CLICK), so the sortable
+      // owns the press outright.
+      {...dragHandleProps}
+      onPointerDown={event => {
+        if ((event.target as HTMLElement).closest('[data-reorder-handle], [data-row-actions]')) {
+          return
+        }
+
+        dragHandleProps?.onPointerDown?.(event)
+      }}
       ref={rowRef}
     >
       <SidebarRowCluster className="min-w-0 flex-1">
@@ -141,6 +153,7 @@ export function ProjectOverviewRow({
             <button
               aria-label={s.projects.toggle(project.label, !open)}
               className="flex flex-1 items-center self-stretch bg-transparent p-0"
+              data-row-actions
               onClick={toggleOpen}
               type="button"
             >

apps/desktop/src/app/chat/sidebar/session-row.tsx

@@ -140,19 +140,26 @@ function SidebarSessionRowImpl({
           className
         )}
         data-working={liveTurn ? 'true' : undefined}
+        // The row runs BOTH drags off one press, and each declines outside its
+        // own region — so no timing/arbitration rule is needed and neither can
+        // steal the other's gesture. Over the sidebar only the reorder has a
+        // target (the session drop denies: side chrome hosts no main tile);
+        // over the tree only the session drop does (no sortable row there).
+        // Whichever one the release lands on is the one that commits.
+        {...dragHandleProps}
         onPointerDown={event => {
-          // Reorder drags belong to dnd-kit (the grab handle); the ⋯ actions
-          // cluster keeps its own gestures. Everything else on the row —
-          // including the row-body BUTTON, the natural grab surface — is a
-          // session drag source: a POINTER drag on the shared drag session
-          // (never native HTML5 DnD: no macOS snap-back, Esc aborts
-          // instantly). Sub-threshold releases stay ordinary clicks, so
-          // resume / pin / open-in-window are untouched.
+          // The grabber already carries these same listeners, and the ⋯
+          // cluster keeps its own gestures.
           if ((event.target as HTMLElement).closest('[data-reorder-handle], [data-row-actions]')) {
             return
           }
 
+          // A POINTER drag on the shared drag session (never native HTML5 DnD:
+          // no macOS snap-back, Esc aborts instantly). Sub-threshold releases
+          // stay ordinary clicks, so resume / pin / open-in-window are
+          // untouched.
           startSessionDrag({ id: session.id, profile: session.profile || 'default', title }, event)
+          dragHandleProps?.onPointerDown?.(event)
         }}
         // Hovering a row from another profile (the all-profiles view) telegraphs
         // a cross-profile resume — start that backend's spawn now so the click