Agent Skills: smalltalk-commenter

Generates and improves CRC-style (Class-Responsibility-Collaborator) class comments for Smalltalk/Tonel classes. Use whenever lint (st-lint) flags a class as missing or having a poor class comment, when the user asks to "add class comments", "document classes in [package]", "check class documentation", or after creating/modifying Tonel files that leave classes undocumented.