feat: workspaces own their sessions; desktop parity; sidebar and settings cleanup

Workspace sessions (docs/plans/desktop-parity, phases 1-5 and 7):
- sessions.lane_id: a workspace lists only the sessions its panes held,
  stamped by bindRunSession (first writer wins, nested `claude -p`
  excluded); GET /api/sessions?lane=&archived=
- session row state dot, double-click rename, archive (sessions.archived_at,
  hides only); the activity bar's duplicate Sessions tab removed
- Fork beside Resume (--fork-session, Claude only), Ctrl/Cmd+click a live
  session opens it in a second pane, a diff line's comment is pasted into
  the workspace's last-focused pane (lib/panePaste.ts)

dashboard_runs stability:
- a pane's previous run is archived as <pane>@<started_at> instead of being
  overwritten by INSERT OR REPLACE
- a run is flagged abandoned only once its tmux session is gone, at boot and
  on the run-heal beat (panes outlive a server restart)

UI:
- sidebar: no footer, language or theme block; small collapse button in the
  brand corner; version + update check in the connection details modal, a
  status-bar dot while a release is out; language in Settings -> General
- one Switch component for every switch, the themed Checkbox for every
  checkbox (no native checkboxes)

Also: AI Tools catalog trimmed to 10 built-ins (custom-file prompt modes
tested through fixtures), and the workspace plans under docs/plans/ (the
multi-user server plan lives in the AgentHub-Server repo).

client/src/components/settings/AiToolsSettings.tsx

@@ -14,6 +14,7 @@
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 
+import { Switch } from "../Switch";
 import { useEffect, useRef, useState } from "react";
 import { useTranslation } from "react-i18next";
 import { ChevronDown, Download, ExternalLink, RefreshCw } from "lucide-react";
@@ -44,7 +45,7 @@ function Homepage({ tool }: { tool: AiTool }) {
   );
 }
 
-function Switch({
+function ToolSwitch({
   tool,
   disabled,
   onToggle,
@@ -55,26 +56,13 @@ function Switch({
 }) {
   const { t } = useTranslation("settings");
   return (
-    <button
-      type="button"
-      role="switch"
-      aria-checked={tool.enabled}
-      aria-label={t("aiTools.enabledOf", { tool: tool.label })}
+    <Switch
+      checked={tool.enabled}
+      onChange={onToggle}
+      label={t("aiTools.enabledOf", { tool: tool.label })}
       title={tool.enabled ? t("aiTools.enabled") : t("aiTools.disabled")}
       disabled={disabled}
-      onClick={onToggle}
-      className={`relative h-5 w-9 shrink-0 rounded-full transition-colors disabled:opacity-50 ${
-        tool.enabled ? "bg-accent" : "bg-surface-4"
-      }`}
-    >
-      <span
-        aria-hidden
-        className={`absolute top-0.5 h-4 w-4 rounded-full bg-white shadow transition-all ${
-          tool.enabled ? "left-[18px]" : "left-0.5"
-        }`}
-      />
-      <span className="sr-only">{tool.enabled ? t("aiTools.enabled") : t("aiTools.disabled")}</span>
-    </button>
+    />
   );
 }
 
@@ -297,7 +285,7 @@ export function AiToolsSettings() {
                       </button>
                     )}
                   </div>
-                  <Switch
+                  <ToolSwitch
                     tool={tool}
                     disabled={busy !== null}
                     onToggle={() =>