v0.2.1

Breaking changes

• Decomposition routines (svd / qr / lq / eigh) now honor a corrected charge-carrying side convention; results may differ when the non-default side was previously selected.
• lazyabstractmethod pattern removed; abstract hooks are now concrete methods on the appropriate *Common mixin. Affects external subclassers of internal mixins.
• Absorb-mode handling standardized via a new Absorb class across linalg modules — accepted values/normalization are unified across sparse and flat backends.

Enhancements

• einsum: multi-term einsum via cotengra contraction paths.
• Cholesky: new cholesky (and cholesky_regularized) for all array types (sparse/flat, abelian/fermionic), with flat-backend support contributed in (#25).
• Decompositions:
  • svd_rand_truncated for randomized truncated SVD.
  • qr_via_cholesky and lq_via_cholesky.
  • svd_via_eig_truncated for the flat backend.
  • svd_via_eig gained an eps parameter for stabilizing small singular values.
  • Flat svd_via_eig now supports the full range of Absorb options and shortcuts.
  • Unified lq, svd, svd_truncated, svd_via_eig, svd_via_eig_truncated, qr, and eigh_truncated onto a shared _split interface in ArrayCommon.
• Performance: lexsort and phase computations reworked for faster jax.jit tracing (#31); int packing dtype tightened.
• Reshape: refactored calc_reshape_args with broader test coverage.
• Architecture: many methods unified into BosonicCommon; new tests/test_no_method_overrides.py enforces the single-definition MRO rule.
• Docs: initial API reference, ReadTheDocs build infrastructure, RTD badge, and reference updates (#30).
• Tooling: pixi run pytest task with SYMMRAY_DEBUG=1; renamed test envs (testpyold/testpymid/testpynew); CI simplified to use the pixi task.

Bug fixes

• Fixed einsum for single-term expressions.
• Fixed reshape with an ambiguous -1 in newshape.
• Fixed charge-carrying side behavior in decompositions.
• Fixed dtype handling in charge shift.
• Fixed cholesky correctness bugs uncovered during multi-backend rollout.

New Contributors

• @ChenAo-Phys made their first contribution in #25

Full Changelog: v0.2.0...v0.2.1