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/codex-mcp/src/lib.rs

@@ -8,11 +8,21 @@ pub use mcp::CODEX_APPS_MCP_SERVER_NAME;
 pub use mcp::McpConfig;
 pub use mcp::ToolPluginProvenance;
 
+pub use auth_elicitation::CodexAppsAuthElicitation;
+pub use auth_elicitation::CodexAppsAuthElicitationPlan;
+pub use auth_elicitation::CodexAppsConnectorAuthFailure;
+pub use auth_elicitation::MCP_TOOL_CODEX_APPS_META_KEY;
+pub use auth_elicitation::auth_elicitation_completed_result;
+pub use auth_elicitation::auth_elicitation_id;
+pub use auth_elicitation::build_auth_elicitation;
+pub use auth_elicitation::build_auth_elicitation_plan;
+pub use auth_elicitation::connector_auth_failure_from_tool_result;
 pub use codex_apps::CodexAppsToolsCacheKey;
 pub use codex_apps::codex_apps_tools_cache_key;
 
 pub use mcp::configured_mcp_servers;
 pub use mcp::effective_mcp_servers;
+pub use mcp::host_owned_codex_apps_enabled;
 pub use mcp::tool_plugin_provenance;
 pub use mcp::with_codex_apps_mcp;
 
@@ -39,6 +49,7 @@ pub use mcp::mcp_permission_prompt_is_auto_approved;
 pub use mcp::qualified_mcp_tool_name_prefix;
 pub use tools::declared_openai_file_input_param_names;
 
+pub(crate) mod auth_elicitation;
 pub(crate) mod codex_apps;
 pub(crate) mod connection_manager;
 pub(crate) mod elicitation;