Expose scheduled tasks in plugin details (#32272)

## What changed

- Add optional `scheduledTasks` metadata to `plugin/read` responses for remote
  plugins, including hourly, daily, weekday, and weekly schedules.
- Preserve the distinction between unavailable metadata (`null`) and a catalog
  response containing no scheduled tasks (`[]`). Local plugin details return
  `null`.
- Export the corresponding Rust, JSON Schema, and TypeScript protocol types.

## Testing

- Cover scheduled-task deserialization and propagation through `plugin/read`.
- Verify missing and empty remote metadata remain distinct.

GitOrigin-RevId: 7af223ed0a1bf6d8f054293084a73f34c6d0332d

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

@@ -663,6 +663,55 @@ pub struct PluginDetail {
     pub apps: Vec<AppSummary>,
     pub app_templates: Vec<AppTemplateSummary>,
     pub mcp_servers: Vec<String>,
+    pub scheduled_tasks: Option<Vec<ScheduledTaskSummary>>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ScheduledTaskSummary {
+    pub key: String,
+    pub name: String,
+    pub prompt: String,
+    pub schedule: ScheduledTaskSchedule,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
+#[serde(tag = "type", rename_all = "camelCase")]
+#[ts(tag = "type")]
+#[ts(export_to = "v2/")]
+pub enum ScheduledTaskSchedule {
+    #[serde(rename_all = "camelCase")]
+    #[ts(rename_all = "camelCase")]
+    Hourly {
+        interval_hours: u32,
+        days: Option<Vec<ScheduledTaskWeekday>>,
+    },
+    #[serde(rename_all = "camelCase")]
+    #[ts(rename_all = "camelCase")]
+    Daily { time: String },
+    #[serde(rename_all = "camelCase")]
+    #[ts(rename_all = "camelCase")]
+    Weekdays { time: String },
+    #[serde(rename_all = "camelCase")]
+    #[ts(rename_all = "camelCase")]
+    Weekly {
+        days: Vec<ScheduledTaskWeekday>,
+        time: String,
+    },
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "SCREAMING_SNAKE_CASE")]
+#[ts(export_to = "v2/")]
+pub enum ScheduledTaskWeekday {
+    Mo,
+    Tu,
+    We,
+    Th,
+    Fr,
+    Sa,
+    Su,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]