- Extract trench channels from original 1F site plan DWG (same origin as
hall frames) via streaming DXF tag parser that walks xref BLOCK contents
and resolves INSERT-chain transforms (missed by top-level iteration,
which caused the earlier 'no trench layer in K2' misjudgment).
- Power trunk plan (E3-59~69) used as cross-validation only: its util-line
xref is a cropped copy (x<=509.2m) with ~3.5m phase offset; angle
clusters (0/+-11/-12 deg) confirm frame rotation alignment.
- Generator tools/cad/extract_trench_seed_k2.py: frame rotation, horizontal
clip (Liang-Barsky), >=30m runs, 1.5m twin-line merge, 6m point sampling
(V61 convention). H6 9 / H7 H8 H9 H10 14 channels each, is_assumed=false.
- All halls H1-H10 now have measured trench (PLANNING R4 resolved).
- Docs: cad-extraction.md V66 section, OWNER_FEEDBACK log.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
