Use thread configuration for app/read (#37891)

## What changed

- Add an optional `threadId` parameter to `app/read`.
- When provided, load the thread's effective configuration before applying app feature gating, workspace policy, and plugin attribution.
- Share the thread-aware configuration loader with `app/list`.

## Testing

- Add coverage showing that `app/read` honors a thread-level connector feature override.

GitOrigin-RevId: 161e910a2d7435ecf4acd0ba9f5f5069d1631f12

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

@@ -3433,6 +3433,7 @@ mod tests {
             request_id: RequestId::Integer(9),
             params: v2::AppsReadParams {
                 app_ids: vec!["app-a".to_string(), "app-b".to_string()],
+                thread_id: None,
                 include_tools: true,
             },
         };
@@ -3440,7 +3441,11 @@ mod tests {
             json!({
                 "method": "app/read",
                 "id": 9,
-                "params": { "appIds": ["app-a", "app-b"], "includeTools": true }
+                "params": {
+                    "appIds": ["app-a", "app-b"],
+                    "threadId": null,
+                    "includeTools": true
+                }
             }),
             serde_json::to_value(&request)?,
         );

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

@@ -177,6 +177,9 @@ pub struct AppsReadParams {
     /// App ids to read. The server accepts at most 100 ids and deduplicates repeated ids while
     /// preserving their first-request order.
     pub app_ids: Vec<String>,
+    /// Optional loaded thread id used to evaluate effective app configuration.
+    #[ts(optional = nullable)]
+    pub thread_id: Option<String>,
     /// When true, include display-only public tool summaries in the returned metadata.
     #[serde(default, skip_serializing_if = "std::ops::Not::not")]
     pub include_tools: bool,