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/js/cards.js

@@ -153,12 +153,15 @@ function buildAgentCard(agent, skills) {
     }
   }
 
+  const effort = (agent.effort || ``).toLowerCase()
+
   card.innerHTML = `
     <div class="card-image">${imageHtml}</div>
     <div class="card-body">
       <div class="card-title-row">
         <span class="card-title">${esc(agent.name)}</span>
         <span class="badge">${prettyModelName(agent.model)}</span>
+        ${effort ? `<span class="badge badge-effort">${effort}</span>` : ``}
       </div>
       ${badges.length ? `<div class="card-badges">${badges.join('')}</div>` : ''}
     </div>