Fix shared-bot Telegram agent resolution and add effort badge

- TelegramService: build the chat context with the session owner instead
  of the bot owner, so a public/shared bot resolves the agent for foreign
  sessions; credentials/CLI permission stay with the bot owner.
- Agent cards: render an effort badge next to the model badge when an
  agent has an explicit reasoning effort set.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

wwwroot/css/dashboard.css

@@ -121,6 +121,12 @@
   color: var(--secondary);
 }
 
+.badge-effort {
+  background: rgb(from var(--info) r g b / .1);
+  border-color: rgb(from var(--info) r g b / .25);
+  color: var(--info);
+}
+
 .section-add-btn {
   font-size: var(--font-size);
 }