# M7 fixtures M7 adds optionals and error unions on top of the M6 ownership model. `ok*.fe` must compile. `bad*.fe` must fail according to the first-line error marker. The files are registered in `src/ferrolang_vm/registry.py`. Coverage: contextual `null`, `?T`, `.?`, `Some`/`None` pattern-only non-destructive views, `mem.replace` extraction, lazy `orelse`/`catch`, nominal error unions, `try`, block/short `catch`, and error code/name uniqueness, plus R4/R7 interactions with optional references/owners.