[codex] Remove redundant plugin app auth state (#27465)

## Summary

- remove the redundant `needsAuth` field from `AppSummary` and generated
app-server schemas
- stop `plugin/read` from querying Apps MCP solely to hydrate unused
connector auth state
- preserve `plugin/install.appsNeedingAuth` membership and
`app/list.isAccessible` as the authentication signals

## Why

Codex App and TUI do not consume `plugin/read.plugin.apps[].needsAuth`.
Hydrating it could establish an Apps MCP connection and discover tools
on a cold `plugin/read` request, adding avoidable latency. The plugin
APIs are still marked under development, so removing this wire field is
preferable to retaining a misleading default.

## Verification

- `just write-app-server-schema`
- `just fmt`
- `just test -p codex-app-server-protocol`
- `just test -p codex-app-server
plugin_install_uses_remote_apps_needing_auth_response`
- `just test -p codex-app-server
plugin_install_returns_apps_needing_auth`
- `just test -p codex-app-server
plugin_read_returns_plugin_details_with_bundle_contents`
- `just test -p codex-tui
plugin_detail_popup_snapshot_shows_install_actions_and_capability_summaries`
- `$xin-build` simplify and debug reviews

codex-rs/tui/src/chatwidget/tests/helpers.rs

@@ -1414,7 +1414,7 @@ pub(super) fn plugins_test_detail(
     description: Option<&str>,
     skills: &[&str],
     hooks: &[(codex_app_server_protocol::HookEventName, usize)],
-    apps: &[(&str, bool)],
+    apps: &[&str],
     mcp_servers: &[&str],
 ) -> PluginDetail {
     PluginDetail {
@@ -1449,12 +1449,11 @@ pub(super) fn plugins_test_detail(
             .collect(),
         apps: apps
             .iter()
-            .map(|(name, needs_auth)| AppSummary {
+            .map(|name| AppSummary {
                 id: format!("{name}-id"),
                 name: (*name).to_string(),
                 description: Some(format!("{name} app")),
                 install_url: Some(format!("https://example.test/{name}")),
-                needs_auth: *needs_auth,
             })
             .collect(),
         app_templates: Vec::new(),

codex-rs/tui/src/chatwidget/tests/popups_and_settings.rs

@@ -654,7 +654,7 @@ async fn plugin_detail_popup_snapshot_shows_install_actions_and_capability_summa
                     (codex_app_server_protocol::HookEventName::PreToolUse, 1),
                     (codex_app_server_protocol::HookEventName::Stop, 2),
                 ],
-                &[("Figma", true), ("Slack", false)],
+                &["Figma", "Slack"],
                 &["figma-mcp", "docs-mcp"],
             ),
         }),
@@ -698,7 +698,7 @@ async fn plugin_detail_popup_hides_disclosure_for_installed_plugins() {
                     (codex_app_server_protocol::HookEventName::PreToolUse, 1),
                     (codex_app_server_protocol::HookEventName::Stop, 2),
                 ],
-                &[("Figma", true), ("Slack", false)],
+                &["Figma", "Slack"],
                 &["figma-mcp", "docs-mcp"],
             ),
         }),