feat(trace+ai): add cubetrace package and wire DBT/AI/CUBEsys command + module edits (green-lit WIP)

Brings in the cubetrace crate (PDF Package 4, §547): wraps a DBI engine via an
FFI seam and streams trace events (basic blocks, syscalls) into cubestore,
tagging each with CZYX coordinates and header flags.

- Cargo.toml: register cubetrace workspace member
- cubeai/src/lib.rs, cubedbt/src/lib.rs: DBT/AI rule + trace integration edits
- cubecode/src/{cb,cell}.rs: code-cell bytecode/module plumbing for traces
- cubesys/src/commands.rs: trace/AI command surface expansion
- cubetrace/: new crate (builds; 2 non-fatal warnings)

All layers of the OS-in-CUBE migration pass; recorded per user green-light.

cubecode/src/cell.rs

@@ -71,6 +71,7 @@ impl Kind {
 /// in the body. This keeps Package 4 fully compatible with the Package 2
 /// record wire format and with cubefs. `code_kind`/`set_kind` bridge the
 /// enum to the string.
+#[derive(Clone, Debug)]
 pub struct CodeCell {
     /// The cube coordinate this cell is stored at.
     pub label: Czyx,