Add output_schema to code mode render (#17210)

This updates code-mode tool rendering so MCP tools can surface
structured output types from their `outputSchema`.

What changed:
- Detect MCP tool-call result wrappers from the output schema shape
instead of relying on tool-name parsing or provenance flags.
- Render shared TypeScript aliases once for MCP tool results
(`CallToolResult`, `ContentBlock`, etc.) so multiple MCP tool
declarations stay compact.
- Type `structuredContent` from the tool definition's `outputSchema`
instead of rendering it as `unknown`.
- Update the shared MCP aliases to match the MCP draft `CallToolResult`
schema more closely.

Example:
- Before: `declare const tools: { mcp__rmcp__echo(args: { env_var?:
string; message: string; }): Promise<{ _meta?: unknown; content:
Array<unknown>; isError?: boolean; structuredContent?: unknown; }>; };`
- After: `declare const tools: { mcp__rmcp__echo(args: { env_var?:
string; message: string; }): Promise<CallToolResult<{ echo: string; env:
string | null; }>>; };`

codex-rs/code-mode/src/lib.rs

@@ -7,13 +7,13 @@ pub use description::CODE_MODE_PRAGMA_PREFIX;
 pub use description::CodeModeToolKind;
 pub use description::ToolDefinition;
 pub use description::ToolNamespaceDescription;
-pub use description::append_code_mode_sample;
 pub use description::augment_tool_definition;
 pub use description::build_exec_tool_description;
 pub use description::build_wait_tool_description;
 pub use description::is_code_mode_nested_tool;
 pub use description::normalize_code_mode_identifier;
 pub use description::parse_exec_source;
+pub use description::render_code_mode_sample;
 pub use description::render_json_schema_to_typescript;
 pub use response::FunctionCallOutputContentItem;
 pub use response::ImageDetail;