fix(workspace): a new tab shows in its workspace; a row opens its tabs

A tab opened bare from + had no session row until its first hook, and
the sidebar re-read its live panes only when a workspace's status or
session moved, which a tab in slots 1-3 never does: the new tab showed
nowhere. The sidebar now lists a live AI tab whose session has no row
yet as "New session" straight from the run (its session id is known
from the start) and follows the Workspace page's own run-list poll
(LIVE_RUNS_EVENT).

A sidebar workspace row now opens the workspace's live tabs on the pane
it last focused, and its home only when it has none; a Home button at
the left end of the tab bar reaches the home of a workspace whose tabs
keep running.

client/src/i18n/locales/en/lanes.json

@@ -401,5 +401,6 @@
   "panes.full": "4 panes is the most a workspace can show",
   "panes.newTerminal": "New terminal",
   "panes.close": "Close pane (its session keeps running as a tab)",
-  "panes.resize": "Resize panes"
+  "panes.resize": "Resize panes",
+  "tabs.home": "Workspace home"
 }

client/src/i18n/locales/vi/lanes.json

@@ -401,5 +401,6 @@
   "panes.full": "Một workspace hiện tối đa 4 pane",
   "panes.newTerminal": "Terminal mới",
   "panes.close": "Đóng pane (session vẫn chạy dưới dạng tab)",
-  "panes.resize": "Đổi kích thước pane"
+  "panes.resize": "Đổi kích thước pane",
+  "tabs.home": "Trang chủ workspace"
 }