feat: Stop archives a session, Sleep keeps it; SSH keys per type (#82); update Auto fix

- Stop (a tab's or pane's X, Close tab) now archives the session it held
  (DELETE /api/run/:id?archive=1); the new Sleep (moon left of the X, and in
  the tab, pane and session right-click menus) stops the pane but keeps the
  session listed to resume later. Shared endRuns in client/src/lib/stopSession.ts.
- Git identity (#82): an account keeps an ED25519 AND an RSA key (AWS
  CodeCommit takes only RSA), every ssh git offers both, and a member's
  ~/.gitconfig gets core.sshCommand so a git typed in a terminal uses them.
- Update dialog: Auto fix starts a Claude Code session on the install
  folder with the failed update's error.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

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

@@ -31,5 +31,9 @@
   "installedTitle": "Version {{version}} is installed but not running",
   "later": "Not now",
   "skipVersion": "Skip this version",
-  "skipVersionHint": "Don't ask again about this version; a newer one will still be offered."
+  "skipVersionHint": "Don't ask again about this version; a newer one will still be offered.",
+  "autoFix": "Auto fix",
+  "autoFixHint": "Open a Claude Code session in the install folder with this error, so an AI agent fixes it and finishes the update.",
+  "autoFixWorkspace": "AgentHub update",
+  "autoFixError": "Could not start the Auto fix session"
 }