Constraint Refactor 3: Merge *NoLabelDuplicates* and *LinkedParameters* into *Repetition*

[Scienfitz]

Closes #874
Based on #880

[Copilot]

Pull request overview

This PR completes the constraint refactor by unifying discrete “pruning” semantics (specification describes what is kept, invertible via exclude=True) and consolidating the former DiscreteNoLabelDuplicatesConstraint / DiscreteLinkedParametersConstraint into a single DiscreteDegeneracyConstraint, while preserving backward compatibility via deprecations and serialization redirects.

Changes:

• Introduce DiscretePruningConstraint with a uniform exclude flag and matching-rows (“kept rows”) implementations across discrete pruning constraints.
• Replace DiscreteExcludeConstraint with DiscreteFilteringConstraint (and deprecate the old name), and merge label-duplicate / linked-parameter constraints into DiscreteDegeneracyConstraint (with deprecation + cattrs redirects).
• Update search space construction, tests, docs, examples, and the pruning order constant rename (DISCRETE_CONSTRAINTS_*_ORDER).

Reviewed changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/test_deprecations.py	Adds deprecation + legacy-deserialization coverage for renamed/merged constraints.
tests/test_campaign.py	Updates campaign tests to use DiscreteFilteringConstraint(..., exclude=True) instead of the deprecated exclude constraint.
tests/serialization/test_constraint_serialization.py	Updates serialization property tests/strategies to reflect new constraint classes.
tests/hypothesis_strategies/constraints.py	Reworks Hypothesis generators to emit DiscreteFilteringConstraint and DiscreteDegeneracyConstraint.
tests/constraints/test_constraints_polars.py	Switches Polars constraint tests to the new degeneracy constraint (including “linked” behavior via exclude=True).
tests/constraints/test_constrained_cartesian_product.py	Renames ordering constant usage and updates scenarios to new constraints.
tests/constraints/test_batch_constraint.py	Updates batch-constraint tests to use filtering constraints with exclude=True.
tests/conftest.py	Updates shared fixtures to use new constraint classes and semantics.
examples/Mixtures/slot_based.py	Updates example usage from no-label-duplicates to degeneracy constraint.
examples/Constraints_Discrete/filtering_constraints.py	Renames/updates the example to show filtering constraints and the new exclude behavior.
docs/concepts/getting_recommendations.md	Updates documentation example to use DiscreteFilteringConstraint(..., exclude=True).
docs/components/constraints.md	Refactors docs to explain pruning constraints + exclude, and documents DiscreteFilteringConstraint and DiscreteDegeneracyConstraint.
CHANGELOG.md	Documents added/changed/deprecated/removed items for the constraint refactor.
baybe/searchspace/utils.py	Applies pruning constraints by type, updates ordering, and adapts Polars/pandas filtering to the new interface.
baybe/searchspace/discrete.py	Updates constraint ordering logic to the new pruning order constant.
baybe/constraints/discrete.py	Implements new/renamed discrete pruning constraints, adds DiscreteDegeneracyConstraint, and adds deprecation factories + legacy structuring redirects.
baybe/constraints/base.py	Introduces DiscretePruningConstraint ABC with exclude semantics and matching-row APIs (pandas + optional Polars).
baybe/constraints/__init__.py	Exposes new constants/classes and maintains deprecated exports.
baybe/campaign.py	Updates candidate toggling to accept pruning constraints (import + runtime type narrowing).

Suppressed comments (1)

baybe/constraints/discrete.py:72

• DiscreteFilteringConstraint does not validate that conditions and parameters have the same length. This can silently ignore parameters (via zip(...)) or raise IndexError in the Polars path (self.parameters[k]). Add an attrs validator to enforce a 1:1 mapping at construction time.

    conditions: list[Condition] = field(validator=min_len(1))
    """List of individual conditions."""

    combiner: str = field(default="AND", validator=in_(_valid_logic_combiners))
    """Operator encoding how to combine the individual conditions."""

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[AVHopp]

Minor comment, but looks quite good to me. Full review once previous PR is merged.

[AdrianSosic]

More things coming, but here already something to work on

[AdrianSosic]

remaining code comments, now looking at doc

[Scienfitz]

we now need to rethink the name, becasue the convention is that the name expresses what is kept, but with default configuration this cosntraints removes repetitions

Simplest suggestions for me:

• DiscreteNoRepetitionConstraint
• DiscreteRepetitionLimitConstraint

[AVHopp]

First variant makes more sense to me - immediately makes clear that no repetitions are kept while the other one would is a bit more obscure imo

[Scienfitz]

I slightly favor the second one, simply because it also remains valid for all values of n_max_repetitions (its always a limit on the repetitions)