feat(agent): sync model when switching agents

When switching agents via the Telegram bot, the model now automatically
syncs to the model configured for that agent in OpenCode config. If the
agent has no model configured, the current model is preserved. Manual
model switching remains independent and unaffected.

Author: jeffusion

src/agent/manager.ts

@@ -26,9 +26,17 @@ export async function getAvailableAgents(): Promise<AgentInfo[]> {
     }
 
     // Filter out hidden agents and subagents (only show primary and all)
-    const filtered = agents.filter(
-      (agent) => !agent.hidden && (agent.mode === "primary" || agent.mode === "all"),
-    );
+    const filtered = agents
+      .filter((agent) => !agent.hidden && (agent.mode === "primary" || agent.mode === "all"))
+      .map((agent) => ({
+        name: agent.name,
+        description: agent.description,
+        color: agent.color,
+        mode: agent.mode,
+        hidden: agent.hidden,
+        steps: agent.steps,
+        model: agent.model ? { modelID: agent.model.modelID, providerID: agent.model.providerID } : undefined,
+      }));
 
     logger.debug(`[AgentManager] Fetched ${filtered.length} available agents`);
     return filtered;
@@ -138,6 +146,12 @@ export function selectAgent(agentName: string): void {
   setCurrentAgent(agentName);
 }
 
+export async function getModelForAgent(agentName: string): Promise<{ modelID: string; providerID: string } | null> {
+  const agents = await getAvailableAgents();
+  const agent = agents.find((a) => a.name === agentName);
+  return agent?.model ?? null;
+}
+
 /**
  * Get stored agent from settings (synchronous)
  * @returns Current agent name or default "build"

src/agent/types.ts

@@ -8,6 +8,10 @@ export interface AgentInfo {
   mode: "subagent" | "primary" | "all";
   hidden?: boolean;
   steps?: number;
+  model?: {
+    modelID: string;
+    providerID: string;
+  };
 }
 
 /**

src/bot/handlers/agent.ts

@@ -1,7 +1,7 @@
 import { Context, InlineKeyboard } from "grammy";
-import { selectAgent, getAvailableAgents, fetchCurrentAgent } from "../../agent/manager.js";
+import { selectAgent, getAvailableAgents, fetchCurrentAgent, getModelForAgent } from "../../agent/manager.js";
 import { getAgentDisplayName } from "../../agent/types.js";
-import { getStoredModel } from "../../model/manager.js";
+import { getStoredModel, selectModel } from "../../model/manager.js";
 import { formatVariantForButton } from "../../variant/manager.js";
 import { logger } from "../../utils/logger.js";
 import { createMainKeyboard } from "../utils/keyboard.js";
@@ -47,7 +47,16 @@ export async function handleAgentSelect(ctx: Context): Promise<boolean> {
     // Select agent and persist
     selectAgent(agentName);
 
-    // Update keyboard manager state
+    const agentModel = await getModelForAgent(agentName);
+    if (agentModel) {
+      selectModel({
+        providerID: agentModel.providerID,
+        modelID: agentModel.modelID,
+        variant: "default",
+      });
+      await pinnedMessageManager.refreshContextLimit();
+    }
+
     keyboardManager.updateAgent(agentName);
 
     // Update Reply Keyboard with new agent, current model, and context