Dynamic block references: custom properties in Properties (stacked on #838) (#853)

* Dynamic blocks: read parameters and actions from AutoCAD files

A dynamic block's evaluation graph (kept as foreign data since #528) is read
into a typed model, `cadcraft_doc::dynblock`, without changing the kept
data: parameters (linear with value sets, point, visibility states,
lookup, base point; polar, XY, rotation, alignment and flip by geometry)
and actions (stretch with its frame and moved vertices, lookup tables;
move, scale, rotate, flip, array, polar stretch by kind), each with its
graph id and the parameters it follows.

- `blocks.dynamic {name}` returns the model as JSON (handles as hex);
  `blocks.list` marks dynamic blocks.
- Counts and values come from the file: capped by the groups present,
  non-finite numbers and missing members skipped.
- Tests: a synthetic DOOR block (visibility, linear list, stretch, lookup),
  its survival through a save, damaged data, and the engine commands.

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

* Dynamic block references: their values and custom properties

A dynamic block reference's extension dictionary says which dynamic block it
shows (AcDbBlockRepresentation ▸ AcDbRepData) and the values it was given
(AppDataCache ▸ ACAD_ENHANCEDBLOCKDATA, one XRECORD per parameter graph id).
`dynblock::reference` reads them; a reference to the dynamic block itself
has the block's values.

- `dynblock::custom_properties`: the Properties palette's Custom section, in
  parameter order, only parameters shown in Properties: visibility state,
  lookup value worked out from the lookup tables (their "no match" name, e.g.
  Custom, when the inputs match no row), distances and point positions in
  drawing units (block units × the reference's scale), with the choices of
  each (states, lookup values, a distance's list).
- Properties: a dynamic block reference shows its dynamic block's name
  instead of its anonymous block's, and a read-only Custom section.
- `blocks.reference {handle}` returns the definition, values and properties.
- Tests: synthetic references (own values, an anonymous block scaled 2, a
  width no lookup row has), survival through a save, the engine command.

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

* DWG: dynamic block lookup parameters keep their name and lookup action

AutoCAD writes a lookup parameter's subclass marker as
AcDbBlockLookUpParameter; the DWG bridge reads AcDbBlockLookupParameter and
matches it exactly, so the parameter's name (303) and lookup action (94)
were lost in DWG files and AutoCAD's lookups stopped working (a visibility
change no longer resized the block). The bridge DXF now uses its spelling.

Found by driving AutoCAD on CADCraft's output.

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

---------

Co-authored-by: Cody Vogt <[email protected]>
Co-authored-by: Claude Opus 5.5 <[email protected]>
Co-authored-by: Brandon Thomas <[email protected]>

docs/file-format-parity.md

@@ -94,6 +94,7 @@ early (#175), but the throughput problem remains. **DWG ≈ 30% read, ≈ 15% wr
 | Objects: VISUALSTYLE, PLOTSETTINGS, materials, field objects and other unmodelled objects | kept raw (#528) | written back as read | not editable |
 | Foreign xdata, extension dictionaries, reactors, unmodelled objects, colour books | kept raw (#528); an entity's xdata is part of the entity, so COPY, MIRROR, ARRAY and paste keep it on the copies (EXPLODE pieces don't) | written back, handles remapped, references to deleted objects dropped | through DWG: xdata on table records and blocks, entity colour books and reactors, custom-class objects lost (acadrust) |
 | Objects: dynamic block data (ACAD_EVALUATION_GRAPH, BLOCK…PARAMETER, BLOCK…ACTION, grips) | read into a model (`dynblock`, `blocks.dynamic`): parameters, visibility states, value sets, stretch and lookup actions; kept raw (#528) | written back as read | not applied to references or editable yet; DWG open and save keep it too (checked with an AutoCAD dynamic block) |
+| Objects: dynamic block data (ACAD_EVALUATION_GRAPH, BLOCK…PARAMETER, BLOCK…ACTION, grips) | read into a model (`dynblock`, `blocks.dynamic`): parameters, visibility states, value sets, stretch and lookup actions; references: their dynamic block, values and custom properties (`blocks.reference`, Properties ▸ Custom, read-only); kept raw (#528) | written back as read | values can't be changed yet; DWG open and save keep it too (checked with an AutoCAD dynamic block) |
 | Foreign xdata, extension dictionaries, reactors, unmodelled objects, colour books | kept raw (#528) | written back, handles remapped, references to deleted objects dropped | through DWG: xdata on table records and blocks, entity colour books and reactors, custom-class objects lost (acadrust) |
 | Handles and owners | entity handles kept; others regenerated | consistent | stable across CADCraft re-saves (#495); other programs' table and object handles renumbered once |
 
@@ -139,6 +140,7 @@ our output in AutoCAD black-box.
 | 2026-10-12 | minor | DXF/DWG save: the Model layout's plot settings are written as CADCraft plots model space, drawing extents scaled to fit (PLOTSETTINGS 74 = 1, 75 = 0), instead of plot type 5 "Layout information", which other programs' Plot dialogs can't use for model space |
 | 2026-10-12 | minor | VIEWPORT frozen layers also written and read as AutoCAD's group 341 layer handles, so third-party viewers honour per-viewport freezing in DXF (DWG converter gap noted) |
 | 2026-10-12 | minor | HATCH: associative hatches inside blocks keep their source objects; boundaries carry `{ACAD_REACTORS}` |
+| 2026-10-12 | minor | Dynamic block references: definition, values and custom properties read (`blocks.reference`, Properties ▸ Custom) |
 | 2026-10-12 | minor | Dynamic block data row: parameters and actions read into a model (`blocks.dynamic`); kept by DXF and DWG save |
 | 2026-10-11 | minor | Rows refreshed for merged work: code pages and `\M+` (#505), MULTILEADER (#459), IMAGE, MLINE/HELIX/REGION/TOLERANCE, VPORT/VIEW/UCS tables, modelled and raw objects, foreign data (#528), DWT templates and user `.lin`/`.pat`/`.pgp` files (#552), PDF output (#567, #571), plotter devices (#564), data extraction (#433, #534); weighted percentages not re-measured |
 | 2026-10-11 | minor | DXF (ASCII and binary) and DWG saved at 2000–2018, 2018 by default (#421) |