fix(agents): preserve model overrides with team mode

Filter host config agent aliases with the same protected builtin-name rules used for external agent sources so stale display-name entries cannot replace resolved user-configured models when team mode is enabled.

Fixes #4429

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/plugin-handlers/agent-config-handler.test.ts

@@ -310,6 +310,62 @@ describe("applyAgentConfig builtin override protection", () => {
     expect(result.SiSyPhUs).toBeUndefined()
   })
 
+  test("filters host config agent display-name aliases before they override resolved builtin models", async () => {
+    // given
+    createBuiltinAgentsSpy.mockResolvedValue({
+      sisyphus: {
+        name: "sisyphus",
+        prompt: "resolved sisyphus prompt",
+        mode: "primary",
+        model: "openai/gpt-5.5",
+      },
+      explore: {
+        name: "explore",
+        prompt: "resolved explore prompt",
+        mode: "subagent",
+        model: "minimax-cn-coding-plan/MiniMax-M2.5-highspeed",
+      },
+      atlas: builtinAtlasConfig,
+    })
+    const config = createBaseConfig()
+    config.agent = {
+      [getAgentListDisplayName("sisyphus")]: {
+        name: getAgentListDisplayName("sisyphus"),
+        prompt: "stale sisyphus prompt",
+        mode: "primary",
+        model: "anthropic/claude-opus-4-7",
+      },
+      [getAgentListDisplayName("explore")]: {
+        name: getAgentListDisplayName("explore"),
+        prompt: "stale explore prompt",
+        mode: "subagent",
+        model: "openai/gpt-5.4",
+      },
+    }
+    const pluginConfig = {
+      ...createPluginConfig(),
+      team_mode: { enabled: true },
+      agents: {
+        sisyphus: { model: "openai/gpt-5.5" },
+        explore: { model: "minimax-cn-coding-plan/MiniMax-M2.5-highspeed" },
+      },
+    } as OhMyOpenCodeConfig
+
+    // when
+    const result = await applyAgentConfig({
+      config,
+      pluginConfig,
+      ctx: { directory: "/tmp" },
+      pluginComponents: createPluginComponents(),
+    })
+
+    // then
+    expect((result[getAgentListDisplayName("sisyphus")] as AgentConfig).model).toBe("openai/gpt-5.5")
+    expect((result[getAgentListDisplayName("explore")] as AgentConfig).model).toBe(
+      "minimax-cn-coding-plan/MiniMax-M2.5-highspeed"
+    )
+  })
+
   test("filters plugin agents whose key matches the builtin display-name alias", async () => {
     // given
     const pluginComponents = createPluginComponents()

src/plugin-handlers/agent-config-handler.ts

@@ -259,24 +259,6 @@ export async function applyAgentConfig(params: {
       agentConfig["OpenCode-Builder"] = override ? { ...base, ...override } : base;
     }
 
-    const filteredConfigAgents = configAgent
-      ? Object.fromEntries(
-          Object.entries(configAgent)
-            .filter(([key]) => {
-              if (key === "build") return false;
-              if (key === "plan" && shouldDemotePlan) return false;
-              if (key in builtinAgents) return false;
-              return true;
-            })
-            .map(([key, value]) => {
-              if (!value) return [key, value];
-              const migrated = migrateAgentConfig(value as Record<string, unknown>);
-              if (!migrated.mode) migrated.mode = "subagent";
-              return [key, migrated];
-            }),
-        )
-      : {};
-
     const migratedBuild = configAgent?.build
       ? migrateAgentConfig(configAgent.build as Record<string, unknown>)
       : {};
@@ -292,6 +274,26 @@ export async function applyAgentConfig(params: {
       ...Object.keys(agentConfig),
       ...Object.keys(builtinAgents),
     ]);
+    const filteredConfigAgentSource = configAgent
+      ? filterProtectedAgentOverrides(
+          Object.fromEntries(
+            Object.entries(configAgent).filter(([key]) => {
+              if (key === "build") return false;
+              if (key === "plan" && shouldDemotePlan) return false;
+              return true;
+            }),
+          ),
+          protectedBuiltinAgentNames,
+        )
+      : {};
+    const filteredConfigAgents = Object.fromEntries(
+      Object.entries(filteredConfigAgentSource).map(([key, value]) => {
+        if (!value) return [key, value];
+        const migrated = migrateAgentConfig(value as Record<string, unknown>);
+        if (!migrated.mode) migrated.mode = "subagent";
+        return [key, migrated];
+      }),
+    );
     const filteredUserAgents = filterProtectedAgentOverrides(
       userAgents,
       protectedBuiltinAgentNames,
@@ -373,16 +375,17 @@ export async function applyAgentConfig(params: {
       protectedBuiltinAgentNames,
     );
 
-    const defaultedConfigAgents = configAgent
-      ? Object.fromEntries(
-          Object.entries(configAgent).map(([key, value]) => {
-            if (!value) return [key, value];
-            const migrated = migrateAgentConfig(value as Record<string, unknown>);
-            if (!migrated.mode) migrated.mode = "subagent";
-            return [key, migrated];
-          }),
-        )
+    const filteredConfigAgentSource = configAgent
+      ? filterProtectedAgentOverrides(configAgent, protectedBuiltinAgentNames)
       : {};
+    const defaultedConfigAgents = Object.fromEntries(
+      Object.entries(filteredConfigAgentSource).map(([key, value]) => {
+        if (!value) return [key, value];
+        const migrated = migrateAgentConfig(value as Record<string, unknown>);
+        if (!migrated.mode) migrated.mode = "subagent";
+        return [key, migrated];
+      }),
+    );
 
     params.config.agent = {
       ...builtinAgents,