feat(cli): aura new — CLI wiring, load-bypass guard, authoring-loop e2e (0103 tasks 2-4)
Command::New + NewCmd + dispatch_new (usage faults exit 2, runtime
refusals exit 1, the C14 partition); the main() guard exempts aura new
from the eager project load so scaffolding works inside unbuilt trees.
E2e (tests/project_new.rs, 6 tests): scaffold -> cargo build ->
aura run twice byte-identical with manifest.project.namespace stamped;
introspect lists the project type beside std; refusals for existing
destination (1), invalid names (2), missing engine path with
--engine-path hint (1); aura new inside an unbuilt project tree
succeeds (the bypass proof); namespace override reaches the built
vocabulary (an additive e2e beyond the plan, kept).
Verification: cargo build --workspace clean; cargo test --workspace
873 passed / 0 failed; clippy -D warnings clean.
refs #180
Brummel
560f594902