Use runtime authentication for OpenAI MCP and app requests (#59749)

## What changed

- Select fresh authentication for each HTTP operation on eligible OpenAI MCP connections while preserving the connection's credential source and account network policy. Stop redirects when requests carry runtime assertions.
- Pass the owning thread's authentication and runtime context through app discovery, connector metadata, and trusted-access requests. Include the runtime authentication mode in MCP connection and tool-cache identities.
- Give resumed actors analytics clients bound to their own authentication context, and serialize stored-credential reloads with token refresh while preserving host-provided credentials.

## Testing

Add coverage for fresh request assertions, revoked account policies, redirect handling, resumed-actor isolation, and MCP uploads in dual-header and assertion-only modes.

GitOrigin-RevId: f06900a6db61cd6cf53c3aa8075afeec4d5706d9

codex-rs/app-server/src/message_processor.rs

@@ -484,7 +484,6 @@ impl MessageProcessor {
             Arc::clone(&model_catalog),
         );
         let apps_processor = AppsRequestProcessor::new(
-            auth_manager.clone(),
             Arc::clone(&thread_manager),
             outgoing.clone(),
             config_manager.clone(),