D059 - A param.sfo is a format and belongs here. An icon is a picture and does not

Both were being shipped as the ASCII word PLACEHOLDER, and both had been filed under "the title's content, which a format library must not invent". Only one of them was.

PSF is a format - a magic, an index, a key table and a data table, with ordering and alignment rules that are wrong in exactly the way a wrong format is wrong. A package carrying twenty-one bytes where the magic goes fails on the first four. selfish_pkg::sfo writes a real one, and reading a real one back is what proves it: examples/param.rs parses the param.sfo out of three real packages - recovering their actual titles - and confirms every field this crate writes has the same type and the same field width as the real files. 3 of 3.

What the values are stays the caller's. Params has no default for the title or its id.

An icon has no encoding this repository owns and no derivation from anything. PNG is a format but it is not one of the console's formats, so by the admission test it fails on the first question. It stays an input.

But an installer still needs a file it can decode, so the tool - not the library - generates one when none is given, and says so on stdout. That placement is the whole distinction: selfish-cli is a convenience, selfish-pkg is knowledge.