feat: add operational timeline workspace

src/features/workbench/workspace/workbench-main-frame.tsx

@@ -12,6 +12,8 @@ import type {
 type WorkbenchMainFrameProps = {
   mapContent: ReactNode;
   mapOverlay?: ReactNode;
+  timelineContent: ReactNode;
+  timelineMode: "compact" | "expanded" | "summary";
   activeArtifact: AnalysisArtifact | null;
   pendingArtifact: AnalysisArtifact | null;
   surfaceMode: WorkbenchSurfaceMode;
@@ -26,6 +28,8 @@ type WorkbenchMainFrameProps = {
 export function WorkbenchMainFrame({
   mapContent,
   mapOverlay,
+  timelineContent,
+  timelineMode,
   activeArtifact,
   pendingArtifact,
   surfaceMode,
@@ -41,8 +45,9 @@ export function WorkbenchMainFrame({
 
   return (
     <div
-      className="workbench-main-frame pointer-events-none absolute inset-x-0 bottom-0 top-14 lg:left-[var(--workbench-agent-current-width)]"
+      className="workbench-main-frame pointer-events-none absolute inset-x-0 bottom-0 top-14 min-h-0 lg:left-[var(--workbench-agent-current-width)]"
       data-testid="workbench-main-frame"
+      data-timeline-mode={timelineMode}
     >
       <div
         id="main-workspace"
@@ -94,16 +99,27 @@ export function WorkbenchMainFrame({
             />
           </section>
         ) : null}
+
+        {pendingArtifact ? (
+          <ArtifactPeekBar
+            artifact={pendingArtifact}
+            surfaceMode={surfaceMode}
+            onOpen={onOpenPendingArtifact}
+            onDestroy={onDestroyPendingArtifact}
+          />
+        ) : null}
       </div>
 
-      {pendingArtifact ? (
-        <ArtifactPeekBar
-          artifact={pendingArtifact}
-          surfaceMode={surfaceMode}
-          onOpen={onOpenPendingArtifact}
-          onDestroy={onDestroyPendingArtifact}
-        />
-      ) : null}
+      <div
+        className={cn(
+          "pointer-events-auto absolute bottom-3 left-3 right-3 z-40 mx-auto min-h-0 w-[calc(100%-1.5rem)]",
+          timelineMode === "expanded" && "max-w-[1180px]",
+          timelineMode === "compact" && "max-w-[980px]",
+          timelineMode === "summary" && "max-w-[760px]"
+        )}
+      >
+        {timelineContent}
+      </div>
     </div>
   );
 }