feat: support disable skills by name. (#15378)

Support disabling skills by name, primarily for plugin skills. We can’t
use the path, since plugin skill paths may change across versions.

codex-rs/app-server-protocol/src/protocol/v2.rs

@@ -3340,6 +3340,7 @@ pub struct SkillSummary {
     pub short_description: Option<String>,
     pub interface: Option<SkillInterface>,
     pub path: PathBuf,
+    pub enabled: bool,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
@@ -3378,7 +3379,12 @@ pub enum PluginSource {
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct SkillsConfigWriteParams {
-    pub path: PathBuf,
+    /// Path-based selector.
+    #[ts(optional = nullable)]
+    pub path: Option<AbsolutePathBuf>,
+    /// Name-based selector.
+    #[ts(optional = nullable)]
+    pub name: Option<String>,
     pub enabled: bool,
 }