fix(run,lanes): prompt autocomplete, per-lane Active runs, compact Changes header

- The run form's prompt box offers suggestions again: `/` lists the run
  cwd's project and user commands and skills plus the CLI built-ins
  (claude lanes only), `@` lists files under the cwd; Enter picks while
  the list is open and sends otherwise. The 2f39f4e rewrite had left a
  bare textarea that ignored both.
- Active runs lists only the current lane's runs and external sessions
  (sessions matched to the lane by longest path-boundary cwd), instead of
  every lane's.
- The Changes panel's git line and its actions are one compact row in one
  card, and the mode/range toolbar is one wrapping row.
- The lane card hides itself when it has nothing to show, instead of
  leaving an empty frame where the git row used to be.

client/src/components/run/LaneConsolePane.tsx

@@ -27,7 +27,7 @@
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 
-import { useCallback, useEffect, useRef, useState } from "react";
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 import { useTranslation } from "react-i18next";
 import { Play, AlertCircle } from "lucide-react";
 import { api } from "../../lib/api";
@@ -47,6 +47,20 @@ import { TerminalView } from "./TerminalView";
 import { RunSetup } from "./RunSetup";
 import { ActiveRunsSwitcher } from "./RunHistory";
 
+/** The claude lane a session's cwd belongs to: the longest path-boundary
+ *  prefix, the same rule the server binds hook sessions with. External
+ *  sessions are all claude — Codex emits no hooks. */
+function owningLaneId(cwd: string, lanes: Lane[]): number | null {
+  let best: Lane | null = null;
+  for (const l of lanes) {
+    if (l.tool !== "claude") continue;
+    const root = l.cwd.replace(/\/+$/, "");
+    if (cwd !== root && !cwd.startsWith(root + "/")) continue;
+    if (!best || root.length > best.cwd.replace(/\/+$/, "").length) best = l;
+  }
+  return best?.id ?? null;
+}
+
 export interface LaneConsolePaneProps {
   lanes: Lane[];
   laneId: number | null;
@@ -97,6 +111,22 @@ export function LaneConsolePane({
 
   const currentLane = laneId !== null ? lanes.find((l) => l.id === laneId) : null;
   const laneTool = currentLane?.tool ?? "claude";
+  // The page polls runs and sessions for EVERY lane; this pane's Active runs
+  // list is this lane's only. No lane selected keeps the full lists.
+  const laneRuns = useMemo(
+    () =>
+      laneId === null || !activeRuns
+        ? activeRuns
+        : { ...activeRuns, items: activeRuns.items.filter((r) => r.laneId === laneId) },
+    [activeRuns, laneId]
+  );
+  const laneSessions = useMemo(
+    () =>
+      laneId === null
+        ? externalSessions
+        : (externalSessions ?? []).filter((s) => s.cwd && owningLaneId(s.cwd, lanes) === laneId),
+    [externalSessions, laneId, lanes]
+  );
   const toolLabel = laneTool === "codex" ? "Codex" : "Claude";
 
   useEffect(() => {
@@ -487,11 +517,11 @@ export function LaneConsolePane({
           </p>
         </div>
         <ActiveRunsSwitcher
-          activeRuns={activeRuns}
+          activeRuns={laneRuns}
           currentHandleId={handle?.id || null}
           onAttach={attachToRun}
           runHistory={runHistory}
-          externalSessions={externalSessions}
+          externalSessions={laneSessions}
           onResumeFromHistory={onResumeFromHistory}
           onViewFromHistory={onViewFromHistory}
           onKill={killRun}