All variable names must now follow @scope/name pattern:
- scope: @[a-zA-Z][a-zA-Z0-9]* (e.g. @myapp, @todo)
- name: one or more segments of [a-zA-Z0-9._-]+
- @ocas/* reserved for internal use
Examples: @myapp/config, @todo/schema, @ocas/schema (builtin)
Rejected: config (no scope), foo/bar (no @), @/foo (empty scope)
Updated validateName() in core, CLI error messages, and all tests.
594 tests pass.
Fixes#29