feat(chat): surface failed turns and add error diagnostics to the status report

A turn that OpenCode stopped could end with nothing on screen: the
session.error event was only turned into a sidebar badge, its message was
dropped (the notification expected a different shape than OpenCode sends),
and a send that was accepted but never answered looked the same as success.

- The chat shows what OpenCode reported under the last message while that
  turn is the latest one, and names a user message an idle session has left
  unanswered for five seconds.
- The last 20 session errors are kept in memory and listed in the status
  report (Ctrl/Cmd+Shift+L, also `__opencodeDebug.statusReport()`), next to
  rejected sends, the managed OpenCode process's last error and stderr
  tail, and the OpenCode and desktop log file locations.
- The OpenCode health probe hits /global/health instead of a route that
  does not exist, and probe URLs resolve against the page for web runtimes.

packages/ui/src/lib/i18n/messages/tr.ts

@@ -1712,6 +1712,9 @@ export const dict = {
   'header.actions.terminalPanelWithShortcut': 'Terminal paneli ({shortcut})',
   'chat.recap.aria': 'Session özeti',
   'chat.recap.label': 'Özet:',
+  'chat.sessionError.title': 'OpenCode bu yanıtı durdurdu',
+  'chat.sessionError.noDetails': 'OpenCode ayrıntı bildirmedi. Son hataları görmek için durum raporunu açın (Ctrl/Cmd+Shift+L).',
+  'chat.sessionError.noReply': 'OpenCode bu mesaja yanıt vermeye başlamadı.',
   'chat.goal.dialog.titleCreate': 'Session hedefi belirle',
   'chat.goal.dialog.titleManage': 'Session hedefi',
   'chat.goal.dialog.objectiveLabel': 'Amaç',