Add visible-only isometric option and #2233 quotation comparison

[pzfreo]

Addresses #2233 with a supported per-view hidden-line setting and a reproducible quotation-sheet comparison.

• Add Sheet view handle hidden_lines(True/False) for principal and pictorial views, defaulting to current behavior.
• Retain ISO while suppressing its hidden edges in the axial blind-hole section example.
• Compare baseline, required section with hidden ISO, and required section with visible-only ISO as PDFs, PNGs, reports, and a measured-fact ledger.
• Document source limitations: the original quotation STEP and edited sheet are unavailable, so this is a synthetic policy test, not a claim about the original connector.

Local verification: 35 view-constraint and issue tests passed; focused issue tests rerun after final edit; Ruff and diff checks passed. On the synthetic part the ISO hidden-edge count changes from 10 to 0; the visible ISO, axial section, H7 fit, measured requirements, and clean lint remain.

Generate PDFs: python docs/examples/quotation_blind_hole.py --out-dir /tmp/draftwright-2233 --date 2026-10-07 --sheet 1/1