ATTDEF: dialog, -ATTDEF prompts, tag display, Properties and ribbon

Attribute Definition dialog and Edit Attribute Definition dialog, -ATTDEF
with the reference prompts and modes (AFLAGS), tag shown in the drawing,
justification-aware grips, reworked Properties with validation, Home Block
slide-out and Insert Block Definition panel, and the codec patch for
ATTDEF DXF output and the R2013+ solid wire cache.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

assets/ocad.pgp

@@ -65,6 +65,7 @@ PC,       *PASTECLIP
 
 ; ── Blocks / references ───────────────────────────────────────────────────
 ATT,      *ATTDEF
+-ATT,     *-ATTDEF
 BE,       *BEDIT
 IAT,      *IMAGEATTACH
 XA,       *XATTACH