Support Codex Apps auth elicitations (#19193)

## Summary

- request URL-mode MCP elicitations when Codex Apps tool calls fail with
connector auth metadata
- route Codex Apps auth URL elicitations into the TUI app-link flow

## Test plan

- `just fmt`
- `cargo test -p codex-core mcp_tool_call::tests`
- `cargo test -p codex-mcp`
- `cargo test -p codex-tui bottom_pane::app_link_view::tests`
- `just fix -p codex-core`
- `just fix -p codex-mcp`
- `just fix -p codex-tui`

Also attempted broader local runs:

- `cargo test -p codex-core` fails in unrelated
config/request-permission/proxy-sensitive tests under the current Codex
Desktop environment.
- `cargo test -p codex-tui` fails in unrelated status
snapshots/trust-default tests because the ambient environment renders
workspace-write/network permission defaults.

codex-rs/core/src/session/mcp.rs

@@ -233,6 +233,8 @@ impl Session {
             .tool_plugin_provenance(config.as_ref())
             .await;
         let mcp_servers = with_codex_apps_mcp(mcp_servers, auth.as_ref(), &mcp_config);
+        let host_owned_codex_apps_enabled =
+            host_owned_codex_apps_enabled(&mcp_config, auth.as_ref());
         let auth_statuses =
             compute_auth_statuses(mcp_servers.iter(), store_mode, auth.as_ref()).await;
         let mcp_runtime_environment = match turn_context.environments.primary() {
@@ -264,6 +266,7 @@ impl Session {
             mcp_runtime_environment,
             config.codex_home.to_path_buf(),
             codex_apps_tools_cache_key(auth.as_ref()),
+            host_owned_codex_apps_enabled,
             tool_plugin_provenance,
             auth.as_ref(),
         )

codex-rs/core/src/session/mod.rs

@@ -307,6 +307,7 @@ use crate::windows_sandbox::WindowsSandboxLevelExt;
 use codex_core_plugins::PluginsManager;
 use codex_git_utils::get_git_repo_root;
 use codex_mcp::compute_auth_statuses;
+use codex_mcp::host_owned_codex_apps_enabled;
 use codex_mcp::with_codex_apps_mcp;
 use codex_otel::SessionTelemetry;
 use codex_otel::THREAD_STARTED_METRIC;

codex-rs/core/src/session/session.rs

@@ -918,6 +918,9 @@ impl Session {
             let enabled_mcp_server_count = mcp_servers.values().filter(|server| server.enabled).count();
             let required_mcp_server_count = required_mcp_servers.len();
             let tool_plugin_provenance = mcp_manager.tool_plugin_provenance(config.as_ref()).await;
+            let host_owned_codex_apps_enabled = config
+                .features
+                .apps_enabled_for_auth(auth.as_ref().is_some_and(|auth| auth.uses_codex_backend()));
             {
                 let mut cancel_guard = sess.services.mcp_startup_cancellation_token.lock().await;
                 cancel_guard.cancel();
@@ -959,6 +962,7 @@ impl Session {
                 mcp_runtime_environment,
                 config.codex_home.to_path_buf(),
                 codex_apps_tools_cache_key(auth),
+                host_owned_codex_apps_enabled,
                 tool_plugin_provenance,
                 auth,
             )