feat: add file info renderer for appending file metadata

Implements a renderer that appends file information such as size,
modification time, permissions, and file type to item labels. Includes
custom formatBytes function and supports relative time display and
optional colorization.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: lambdalisue

builtin/renderer/mod.ts

@@ -1,8 +1,10 @@
 // This file is generated by gen-mod.ts
 export * from "./absolute_path.ts";
+export * from "./buffer_info.ts";
 export * from "./file_info.ts";
 export * from "./helptag.ts";
 export * from "./nerdfont.ts";
 export * from "./noop.ts";
 export * from "./relative_path.ts";
+export * from "./smart_grep.ts";
 export * from "./smart_path.ts";