Two review findings on the P&ID critique focuses.
The graph's own `nearest` is computed over every port in its grid, including
the `p1..pn` ports it invents on a promoted unknown_block, so a free end near
a sheet frame was hinted to connect to the frame — a call `pid_line_draw`
refuses, since the frame carries no ACADMCP_PID payload. Every dangling row
is now re-hinted over connectable ports only (catalogue / XDATA nodes,
declared ports), so every hint is executable.
`signal_unknown` — the class the reader assigns to a signal-layer line whose
exact class it cannot tell — was skipped by the incompatibility check
because it is not in the drawable class table. Its kind is still signal, so
a signal-layer line ending on a process port is now an error as spec §11.1
requires; only an unclassified line is skipped.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd