feat: v2.5.4 — Query Explorer folded into Sessions, Windows picker and paths

- Sessions page tabs: Sessions · Events · Agents. QueryExplorer.tsx became
  AgentsTable.tsx (agents only — sessions and events already had tabs);
  /query redirects to /sessions?view=agents and leaves the sidebar.
  GET /api/query is unchanged and still answers all three entities.
- Windows picker opens in front: -EncodedCommand script spends the hidden
  first ShowWindow that windowsHide gives the process, then brings the TopMost
  owner forward via AttachThreadInput (v2.5.3's owner was itself hidden).
- Session page Resume/Fork/Open pane: owningLane and sessionWorktreeName
  match Windows folders (either separator), with a test.

client/src/components/lanes/WorkspaceSessionList.tsx

@@ -66,9 +66,10 @@ export function liveRunFor(lane: Lane, runs: RunHandle[], sessionId: string): Ru
 /** The name of the git worktree a session ran in (`claude --worktree` puts it
  *  at `<repo>/.claude/worktrees/<name>`), or null for one in the folder. */
 export function sessionWorktreeName(lane: Lane, s: Session): string | null {
-  const strip = (p: string) => p.replace(/\/+$/, "");
+  // Either separator: a Windows cwd is `D:\repo\.claude\worktrees\<name>`.
+  const strip = (p: string) => p.replace(/[\\/]+$/, "");
   if (!s.cwd || strip(s.cwd) === strip(lane.cwd)) return null;
-  return /\/\.claude\/worktrees\/([^/]+)\/?$/.exec(s.cwd)?.[1] ?? null;
+  return /[\\/]\.claude[\\/]worktrees[\\/]([^\\/]+)[\\/]?$/.exec(s.cwd)?.[1] ?? null;
 }
 
 /** A session row's dot: waiting for the user, failed, held by a live pane, or