Draftwright 0.4.28

Recognition of turned parts is substantially more accurate, and a part that draftwright cannot
fully describe now produces a drawing that says so instead of producing nothing.

Three changes alter existing behaviour. Read these before upgrading.

• An unauthored general tolerance is no longer invented. The title block used to default to
  ISO 2768-m, asserting a manufacturing requirement on every drawing whose caller supplied
  none — including every STEP-derived generated script. It now states UNSPECIFIED. Pass
  tolerance="ISO 2768-m" explicitly to keep the old output; tolerance="" leaves the cell
  blank (#1157, and this dissolves #501).
• Turned-step recognition changed, through Quiddity 0.2.6 → 0.2.8. Rounded plate corners and
  parallel offset cylinders no longer form a false stepped shaft, a modelled thread is no longer
  read as one shoulder per turn, and contiguous equal-diameter bands coalesce into the single
  span they physically are. Drawings of turned parts may show different diameter and length
  callouts than 0.4.27 — in every case measured, fewer false ones (#1555, #1135).
• A partial turned profile warns instead of raising. generate_sheet_script and
  Sheet.build() used to raise ValueError when declared step() segments did not span the
  body, which meant no script and no drawing at all. They now build and report
  turned_profile_not_spanned, naming the undescribed stretch. A hand-authored .step()
  misuse — #631's original case — is therefore a warning rather than an error (#1132).

New diagnostics.

• Sheet can now reconcile AP242 PMI. Pass Sheet(part, source="part.step", pmi="annotate");
  generated scripts do this for you. Unlowered records report pmi_not_lowered, content with no
  census behind it reports pmi_unreconciled, and a declaration claiming a source identity the
  document does not contain reports pmi_source_unknown. Previously a script-built drawing ran
  no PMI reconciliation at all — deleting a raw PMI record changed nothing it reported (#1563).
• lint_summary()["pmi"] now names the document it was reconciled against, with its sha256.

Fixed. On a geometry-only import, lint_summary()["score"] no longer rises when declared
features are removed (#1126). The score remains a severity heuristic, not a quality verdict —
read lint_summary()["quality"] for that.

Quiddity is pinned to 0.2.8.

Full changelog: v0.4.27...v0.4.28