fix(zcode): remove incompatible npm provider field

Stop writing the OpenCode-specific npm field and clean up values
left by earlier versions when synchronizing ZCode configuration.
Add regression coverage for both app and CLI configs.

Closes #231

src-tauri/src/agents/configuration.rs

@@ -2856,6 +2856,9 @@ fn build_zcode_config(
         })
         .collect::<serde_json::Map<_, _>>();
     let managed_provider = ensure_json_object_entry(providers, MANAGED_AGENT_PROVIDER_ID);
+    // `npm` is an OpenCode provider field. ZCode treats it as an incompatible
+    // provider definition, so also remove values written by earlier versions.
+    managed_provider.remove("npm");
     managed_provider.insert("enabled".to_string(), serde_json::json!(true));
     managed_provider.insert("name".to_string(), serde_json::json!("EasyCLIProxyAPI"));
     managed_provider.insert("source".to_string(), serde_json::json!("custom"));
@@ -2865,7 +2868,6 @@ fn build_zcode_config(
         "apiFormat".to_string(),
         serde_json::json!("anthropic-messages"),
     );
-    managed_provider.insert("npm".to_string(), serde_json::json!("@ai-sdk/anthropic"));
     let options = ensure_json_object_entry(managed_provider, "options");
     options.insert("baseURL".to_string(), serde_json::json!(base_url));
     options.insert("apiKey".to_string(), serde_json::json!(api_key));

src-tauri/src/tests/agent_configuration.rs

@@ -910,7 +910,7 @@ fn zcode_agent_config_preserves_other_providers_and_uses_anthropic_messages() {
     models[1].context_window = Some(272_000);
     let rendered = build_zcode_agent_config(
         Some(
-            r#"{"locale":"zh-CN","provider":{"other":{"kind":"openai"},"cpa-gui":{"custom":"keep","options":{"timeout":30}}}}"#,
+            r#"{"locale":"zh-CN","provider":{"other":{"kind":"openai"},"cpa-gui":{"custom":"keep","npm":"@ai-sdk/anthropic","options":{"timeout":30}}}}"#,
         ),
         "http://127.0.0.1:8317",
         DEFAULT_API_KEY,
@@ -939,6 +939,9 @@ fn zcode_agent_config_preserves_other_providers_and_uses_anthropic_messages() {
         value["provider"][MANAGED_AGENT_PROVIDER_ID]["apiFormat"],
         "anthropic-messages"
     );
+    assert!(value["provider"][MANAGED_AGENT_PROVIDER_ID]
+        .get("npm")
+        .is_none());
     assert_eq!(
         value["provider"][MANAGED_AGENT_PROVIDER_ID]["options"]["baseURL"],
         "http://127.0.0.1:8317"
@@ -1000,6 +1003,9 @@ fn zcode_cli_config_sets_main_model_and_both_configs_must_match() {
     assert_eq!(cli_value["model"]["main"], "cpa-gui/gpt-test");
     assert_eq!(cli_value["model"]["lite"], "other/lite");
     assert_eq!(cli_value["plugins"]["keep"], true);
+    assert!(cli_value["provider"][MANAGED_AGENT_PROVIDER_ID]
+        .get("npm")
+        .is_none());
     fs::write(&paths[0], app_config).unwrap();
     fs::write(&paths[1], &cli_config).unwrap();
     assert_eq!(