Add coordinated dual-arm atomic actions

[skywhite1024]

Summary

• Add coordinated placement and coordinated pickment atomic actions for dual-arm workflows.
• Add typed targets/state, exports, API docs, demos, and GLB tutorial assets.
• Add focused tests for coordinated target/state/action behavior.

Validation

• python3 -m py_compile core/actions/init files, coordinated demos, and atomic action tests
• git diff --check

Note: Full pytest in the local conda environment aborts during DexSim/Optix CUDA initialization on this machine.