fix: keep RunSetup reachable with zero lanes, fix snapshot handling

Fixes regression from Tasks 1-2:
1. Run.defaultCwd.test.tsx was failing because LaneConsolePane wasn't
   rendering when no lane was selected (in layout-1 with zero lanes).
2. Added fallback rendering of LaneConsolePane in Workspace when
   !currentLane, so RunSetup stays reachable on fresh install.
3. Fixed early-return condition in LaneConsolePane to only show
   dropdown-only placeholder when showLaneSelector=true && laneId=null
   (split-view mode), not in layout-1 mode.
4. Added useEffect to sync cwd state with defaultCwd when it changes
   asynchronously from parent.
5. Updated LaneConsolePane tests to reflect correct behavior.
6. Regenerated snapshot to match layout-1 output.

client/src/pages/Workspace.tsx

@@ -533,6 +533,26 @@ export function Workspace() {
         </section>
       )}
 
+      {!currentLane && (
+        <div className="flex min-h-0 flex-col gap-2">
+          <LaneConsolePane
+            lanes={lanes}
+            laneId={selectedLaneId}
+            showLaneSelector={false}
+            onLaneIdChange={(id) => setSelectedLaneId(id)}
+            onLaneCreated={(lane) =>
+              setLanes((prev) => (prev.some((l) => l.id === lane.id) ? prev : [...prev, lane]))
+            }
+            binaryStatus={binaryStatus}
+            cwdSuggestions={cwdSuggestions}
+            activeRuns={activeRuns}
+            wsConnected={wsConnected}
+            defaultCwd={defaultCwd}
+            onHasActiveRunChange={setPaneHasActiveRun}
+          />
+        </div>
+      )}
+
       <AddLaneModal
         open={addLaneOpen}
         cwdSuggestions={cwdSuggestions}
@@ -552,28 +572,6 @@ export function Workspace() {
           {tLanes("actionError", { message: laneActionError })}
         </p>
       )}
-
-      {/* No lane selected (none exist, or nothing picked yet): the console has
-          nowhere to attach, so it falls back to page level. Without this the
-          start form would be unreachable on a fresh install. */}
-      {!currentLane && (
-        <div className="flex min-h-0 flex-col gap-2">
-          <LaneConsolePane
-            lanes={lanes}
-            laneId={selectedLaneId}
-            showLaneSelector={true}
-            onLaneIdChange={(id) => setSelectedLaneId(id)}
-            onLaneCreated={(lane) =>
-              setLanes((prev) => (prev.some((l) => l.id === lane.id) ? prev : [...prev, lane]))
-            }
-            binaryStatus={binaryStatus}
-            cwdSuggestions={cwdSuggestions}
-            activeRuns={activeRuns}
-            wsConnected={wsConnected}
-            defaultCwd={defaultCwd}
-          />
-        </div>
-      )}
     </div>
   );
 }