Closes the four verified BLOCKING findings on pid_graph.
1. scope="all" attached across layouts: the port grid, bbox candidates,
vertex grid, junctions and text lookup were pooled from every space.
The grid is now keyed by (space, cell) and every lookup filters by the
edge's space; junctions carry `space`.
2. A mirrored INSERT (extrusion -Z, as MIRROR3D / foreign DXFs store it)
got its catalogue ports on the unmirrored image at 1.0. Both engines
report `mirrored` on INSERT properties (ezdxf: extrusion z < 0; COM:
Normal z < 0; default False); transform_port takes `mirrored` and
applies x -> -x about the WCS insertion point after rotation/scale,
direction (180 - d) mod 360 — cross-checked against Insert.matrix44.
resolve_endpoint passes it through too, so draw_line starts on the
mirror image as well.
3. The text-tag fallback searched a full circle around the box top, so a
line label or note below the symbol beat the tag above it. Candidates
must now sit at or above top - height/2 (spec §9.2 step 6), nearest
wins, and line-number texts are never equipment tags.
4. A non-uniform INSERT scale re-ran the transform with the X factor and
set `inferred` (reserved for foreign-block ports). transform_port
gains `strict=False` for the reader: point ports scale per axis
exactly; a radial port keeps min(sx, sy)·r and the node drops to 0.6
with notes ["non-uniform scale"]. Node dicts gain `y_scale`,
`mirrored` and `notes` (default []).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
