Scope MCP app resource reads to their originating call (#39187)

## Why

App widgets need to read resources using the app and account context of the
tool call that produced them, including after a thread is restored.

## What changed

- Add an optional `originCallId` to `mcpServer/resource/read` requests and
  return it on successful scoped reads.
- Track bounded provenance for successful app tool calls in thread history and
  use the current tool binding, account link, and app policy when reading the
  associated widget resource.
- Reject missing, mismatched, failed, or ambiguous origins, while keeping
  app-only tools available for widget reads without exposing them to the model.

## Testing

Add app-server coverage for scoped widget reads across both history modes,
ephemeral and persistent threads, server restarts, app-only visibility, and
invalid origin cases.

GitOrigin-RevId: 11eaefc066b2a3b639599e4cbdef680233d150a2

codex-rs/codex-mcp/src/lib.rs

@@ -102,6 +102,7 @@ mod openai_docs_source_attribution;
 mod pagination;
 mod plugin_config;
 mod resource_client;
+mod resource_origin;
 pub(crate) mod rmcp_client;
 pub(crate) mod runtime;
 pub(crate) mod server;