M14.4: robustness docs name the library fuzzing and main's brands gate

docs/development.md lists the library files import_fuzz now covers, and the
PR template's CI checklist includes `cargo xtask brands`, which main added
after the no-panics branch was cut.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.github/pull_request_template.md

@@ -8,7 +8,7 @@
 
 ## Checklist
 
-- [ ] `cargo xtask ci` passes (fmt, clippy, tests, assets, layers, wasm).
+- [ ] `cargo xtask ci` passes (fmt, clippy, tests, assets, brands, layers, wasm).
 - [ ] No panics in shipped code: no `unwrap()`, `expect()`, `panic!`, `unreachable!`, `todo!` or
       `unimplemented!` outside tests, and no unchecked indexing on data from files, parameters or
       messages. Errors are returned as `Result` and shown to the user