feat(workspace): split menus start AI tools; drop the Tools menu

A pane's split right/down menus offered only New terminal. They now list
the same AI tools as the tab bar's + menu (newTabTools/newTabBody,
shared from ConsoleTabs), started bare in the first free slot on that
side of the pane.

The tab bar's Tools menu is gone: its readme run hit 409 ERUNLIVE
whenever slot 0 was live (always, in the session view) and depended on
a personal skill; MCP sync and the dev-sync check served the dormant
ship-feature-lane pipeline. The sidebar row menu's readme item goes too.
The routes stay, reached by `agenthub lanes mcp sync` and
`agenthub lanes sync-base`.

Also: the home's Memory header and file tabs no longer shrink (a long
file squeezed the tab row and clipped it).

client/src/pages/Workspace.tsx

@@ -61,7 +61,7 @@ import type { Lane, LaneFeature, ProofFeature } from "../lib/types";
 import { keepIfSame } from "../lib/keepIfSame";
 import { useLanes } from "../hooks/useLanes";
 import { LaneConsolePane } from "../components/run/LaneConsolePane";
-import { ConsoleTabs } from "../components/run/ConsoleTabs";
+import { ConsoleTabs, newTabBody, newTabTools } from "../components/run/ConsoleTabs";
 import { type LayoutUpdate, PaneGrid, SplitMenus, usePaneLayout } from "../components/run/PaneGrid";
 import {
   type Edge,
@@ -77,7 +77,7 @@ import { useAiTools } from "../hooks/useAiTools";
 import { freeSlot } from "../components/lanes/WorkspaceHome";
 import { LIVE_RUNS_EVENT } from "../components/WorkspaceTree";
 import PipelineMap from "../components/lanes/PipelineMap";
-import LaneCard, { since, LaneToolsMenu } from "../components/lanes/LaneCard";
+import LaneCard, { since } from "../components/lanes/LaneCard";
 import { AddLaneModal } from "../components/lanes/AddLaneModal";
 import { LaneChangesPanel } from "../components/lanes/LaneChangesPanel";
 import { WorkspaceHome } from "../components/lanes/WorkspaceHome";
@@ -285,16 +285,19 @@ function ConsoleArea({
     else onNewSession?.();
   };
 
-  // A split menu's "New terminal": a shell in the first free slot, placed on
-  // that side of the pane — unless the workspace changed while it started.
+  // A split menu's "New terminal" or AI tool (bare, as the tab bar's `+`
+  // starts it) in the first free slot, placed on that side of the pane —
+  // unless the workspace changed while it started.
   const free = lane ? freeSlot(lane.id, tabs) : null;
-  const newSplit = async (target: number, edge: Edge) => {
+  const splitTools = lane ? newTabTools(lane, aiTools) : [];
+  const newSplit = async (target: number, edge: Edge, tool?: string) => {
     if (!lane || free === null) return;
     const laneId = lane.id;
     const slot = free;
     setSplitError(null);
     try {
-      const r = await api.lanes.action(laneId, "start", { slot, shell: true });
+      const body = tool ? newTabBody(tool, lane, aiTools) : { shell: true };
+      const r = await api.lanes.action(laneId, "start", { slot, ...body });
       onRunsChanged();
       if (!r.run_id || laneRef.current !== laneId) return;
       pending.current.set(slot, activeRuns);
@@ -327,11 +330,10 @@ function ConsoleArea({
           }}
           onClosed={(runId) => ended(slotOf(runId))}
           onHome={onNewSession}
-          // Per-workspace actions (mcp sync, sync-base check, readme), and
-          // while one pane is shown its split menus (a split pane has its own).
+          // While one pane is shown, its split menus (a split pane has its own).
           actions={
-            <div className="flex items-center gap-1">
-              {shown.length === 1 && shown[0] !== undefined && (
+            shown.length === 1 && shown[0] !== undefined ? (
+              <div className="flex items-center gap-1">
                 <SplitMenus
                   slot={shown[0]}
                   shown={shown}
@@ -340,11 +342,12 @@ function ConsoleArea({
                   // A layout never saved is the one-pane `view`: split that.
                   onChange={(fn) => change((l) => fn(l.root ? l : view))}
                   canStart={free !== null}
-                  onNewSplit={(target, edge) => void newSplit(target, edge)}
+                  tools={splitTools}
+                  toolLabel={aiTools.label}
+                  onNewSplit={(target, edge, tool) => void newSplit(target, edge, tool)}
                 />
-              )}
-              <LaneToolsMenu lane={lane} />
-            </div>
+              </div>
+            ) : undefined
           }
         />
       )}
@@ -360,7 +363,9 @@ function ConsoleArea({
         label={label}
         onChange={change}
         canStart={free !== null}
-        onNewSplit={(target, edge) => void newSplit(target, edge)}
+        tools={splitTools}
+        toolLabel={aiTools.label}
+        onNewSplit={(target, edge, tool) => void newSplit(target, edge, tool)}
         renderPane={(slot) => (
           <LaneConsolePane
             lanes={lanes}

client/src/pages/__tests__/Workspace.test.tsx

@@ -25,6 +25,7 @@ type LaneFixture = {
   detected_signal: string | null;
   run_id: string | null;
   active_feature_id?: number | null;
+  tool?: string;
 };
 
 let lanesToReturn: LaneFixture[] = [
@@ -806,6 +807,17 @@ describe("split panes", () => {
     expect(api.lanes.action).toHaveBeenCalledWith(1, "start", { slot: 2, shell: true });
   });
 
+  it("a split menu starts an AI tool, bare, in the first free slot", async () => {
+    lanesToReturn = lanesToReturn.map((l) => ({ ...l, tool: "claude" }));
+    withRuns([live(0), live(1)]);
+    await open("/workspace?lane=1&run=agenthub-lane-1");
+    await ctrlClick(screen.getByTestId("console-tab-1"));
+    const user = userEvent.setup();
+    await user.click(screen.getByTestId("pane-split-right-1"));
+    await user.click(screen.getByTestId("pane-split-new-right-1-claude"));
+    expect(api.lanes.action).toHaveBeenCalledWith(1, "start", { slot: 2, prompt: "" });
+  });
+
   it("with one pane, the split menus sit beside Tools and split it", async () => {
     withRuns([live(0), live(1)]);
     await open("/workspace?lane=1&run=agenthub-lane-1");