User macros now correctly override setup macros instead of
last-write-wins. Also hardens @def continuation parsing to reject
trailing backslash at EOF, blank lines, and comment lines.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
User macros already overwrote setup macros, so two separate maps were
unnecessary. Also prevents @def continuations from silently swallowing
command or directive lines, and stops expanding macros in teardown.
Macros let setup files define reusable command shorthands that
test files can invoke by name or override with their own definition.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
