Warnings about unreadable instruction files now give a reason and stay short

Instruction files are files Claude Code reads to learn how you want it to work. When some of them cannot be read, the warning used to show one line per file with an icon and the file name. It is now a list where each entry shows the file's path, shortened if it is long, together with the reason it could not be read. When many files are affected, the list ends with a summary of how many more there are.

The same list is used in the warning about instruction files that will slow Claude Code down, which also reports files that are large or too numerous.