v0.3.0

Changed

Model layer migrated from Pydantic to didactic

• Every pydantic.BaseModel and @dataclass model in bead.data, bead.items,
  bead.tokenization, bead.resources, bead.lists, bead.participants,
  bead.config, bead.active_learning.config, bead.dsl.ast,
  bead.deployment.distribution, bead.deployment.jspsych.config,
  bead.behavioral.analytics, bead.templates.filler.FilledTemplate, and
  bead.transforms.base.TransformContext now extends dx.Model (or
  dx.TaggedUnion for the discriminated unions in bead.lists.constraints and
  bead.dsl.ast).
• All models are frozen by default; mutating add_* / update_modified_time
  methods become pure with_* / touched methods that return new instances.
  Cross-field @model_validator(mode="after") checks extract to free
  validate_* functions that callers invoke explicitly.
• list[T] field declarations become tuple[T, ...]; nested-Model fields wrap
  with dx.Embed[T]. Heterogeneous tuples (e.g. tuple[int, int] for scale
  bounds, tuple[UUID, UUID] for ordering precedence pairs) become small
  named records (ScaleBounds, OrderingPair).
• dict[UUID, X] and dict[int, X] mappings become tuples of records
  (ConstraintSatisfaction, ScalePointLabel, etc.) — didactic dict keys must
  be str. dict[str, JsonValue] replaces dict[str, Any].
• Path-typed configuration fields (PathsConfig.data_dir, LoggingConfig.file,
  TrainerConfig.logging_dir, TemplateConfig.mlm_cache_dir,
  ResourceConfig.{lexicon,templates,constraints}_path,
  ModelMetadata.{training_data_path,eval_data_path,best_checkpoint}) are
  stored as str; callers wrap with pathlib.Path on access. Will revert to
  Path once panproto/didactic#21 lands.
• ExperimentConfig.instructions no longer accepts a bare str; pass
  InstructionsConfig.from_text("...") for a single-page string.
• BeadBaseModel.update_modified_time() (mutating) renamed to touched()
  (pure, returns a new instance).

Toolchain

• requires-python raised to >=3.14; pyright pythonVersion and ruff
  target-version follow.
• pydantic removed from project dependencies; didactic>=0.4.3 and
  panproto>=0.43 added.

Added

Transforms (bead.transforms)

• TransformContext carrying span metadata (lemma, POS, head index, tokens) for value-level transformations
• TransformRegistry for registering and resolving named transform pipelines
• morphology transforms: inflection adjustments driven by InflectionSpec
• text transforms: case and whitespace normalizers
• Pipeline syntax [[label|transform1|transform2]] in prompt span references; transforms resolve display text against the registry at trial generation time
• 69 tests covering registry, morphology, text, and prompt integration

Changed

• bead.deployment.jspsych.trials accepts an optional TransformRegistry and passes it through prompt resolution
• Prompt span reference regex now recognizes the |transform suffix on [[label]] and [[label:text]] forms