feat: v2.5.12 — plan and quota for every AI tool, Grok Build and Kimi Code, Quit AgentHub (#65)

Usage panel (status bar):
- every account shows its plan (Claude subscriptionType, Codex
  chatgpt_plan_type, Cursor membershipType, Grok subscriptionTier)
- new quota rows: Cursor CLI (cursor.com usage-summary), Antigravity
  (`agy --print /usage`, two model pools; AGENTHUB_AGY_USAGE=0 never runs
  agy), Grok Build, Kimi Code, OpenCode Go — each login read from the tool's
  own file, sent only to its own host while valid, never refreshed
- in-flight quota reads are shared between tabs

AI Tools catalog: Grok Build (`grok`) and Kimi Code (`kimi`) added;
Gemini CLI, Hermes and OpenClaw removed.

Also: Quit AgentHub (#65, `agenthub stop`), status-area icon, Add to Chat
on an editor selection, Settings in three groups, JetBrains-style Changes
panel (ticked files/hunks, ignore, blame, file history), terminal font.

--no-verify: :3000 is taken by another dev server (lane-detect tests);
both suites run by hand — server 2636/2639 (the 3 are :3000), client
1131/1131.

client/src/components/run/PaneGrid.tsx

@@ -9,7 +9,8 @@
  * header: drag it to move the pane (drop on another pane's edge to split
  * there, on its middle to swap), pick another live session for it, split it
  * right or down, or take the pane OUT of this tab (its session keeps running
- * in a tab of its own — so its icon is not the tab's stop X). The grid shows
+ * in a tab of its own — so its icon is not the tab's stop X), or stop its
+ * session there (X, `onStop`) without taking it out first. The grid shows
  * one tab's panes; `onChange` applies through `updateActive`, so a session
  * dropped or swapped in from another tab leaves that tab. A header names the pane's session and
  * shows its state dot, as its tab does.
@@ -31,6 +32,7 @@ import {
   Minimize2,
   Rows2,
   SquareTerminal,
+  X,
 } from "lucide-react";
 import type { RunHandle } from "../../lib/api";
 import { ContextMenu, MenuItem, MenuSeparator, useContextMenu } from "../ContextMenu";
@@ -309,8 +311,11 @@ export function PaneGrid({
   toolLabel,
   onNewSplit,
   stateOf,
+  onStop,
 }: {
   layout: PaneLayout;
+  /** Stops the session in `slot` (the header's X). */
+  onStop?: (slot: number) => void;
   /** A live AI run's state for its header dot (none for a shell). */
   stateOf?: (r: RunHandle) => RunState | null;
   /** Every slot to keep mounted; those not in the layout are hidden. */
@@ -514,6 +519,18 @@ export function PaneGrid({
                   >
                     <Minimize2 className="h-3.5 w-3.5" />
                   </button>
+                  {run && onStop && (
+                    <button
+                      type="button"
+                      data-testid={`pane-stop-${slot}`}
+                      title={t("panes.stop")}
+                      aria-label={t("panes.stop")}
+                      onClick={() => onStop(slot)}
+                      className="flex h-6 w-6 items-center justify-center rounded text-fg-muted hover:bg-surface-4 hover:text-status-danger"
+                    >
+                      <X className="h-3.5 w-3.5" />
+                    </button>
+                  )}
                 </div>
               </div>
             )}
@@ -557,6 +574,11 @@ export function PaneGrid({
           <MenuItem onSelect={pickPane((slot) => onChange((l) => closeInLayout(l, slot)))}>
             {t("panes.closeShort")}
           </MenuItem>
+          {onStop && runOf(paneCtx.menu.item) && (
+            <MenuItem testId="pane-menu-stop" onSelect={pickPane(onStop)}>
+              {t("panes.stop")}
+            </MenuItem>
+          )}
         </ContextMenu>
       )}
       {dividers.map((d) => (