Support Color in the Python adapter generator; map Leader.override_color

Color converts as {'kind': ByLayer|None|ByBlock|Index|Rgb, 'value': ...}.
Leader.override_color is now writable; neither DWG nor DXF stores it, which
is recorded as a fourth persistence blocker with a canary assertion.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docs/plugin-host-model-coverage-ledger.md

@@ -28,7 +28,7 @@ Completion gate codes: **C** = create through Python document model; **R** = rea
 | AttributeDefinition | **Integration-tested / DXF blocker pending revalidation** | Host commit `5b854bd1` maps block ownership plus every stable ATTDEF field except the nested `embedded_mtext` payload, which is snapshot-readable and preserved untouched. `staged_python_attribute_definition_lifecycle_over_real_ipc` passes C/R/E/D/U/I/V/P with a real block record, Block/BlockEnd markers and linked Insert: high-level creation inside the block, readback, grouped placement/default/rotation/width edits, selection, rendered text, atomic tag/height/style/owner rejection, deletion persistence, and three-step undo/redo. DWG reopens with the full edited state. DXF reopens identity, ownership, tag, prompt, value, placement, height and rotation, and OCS no longer double-converts ATTDEF/ATTRIB rotation. **W remains open:** acadrust `568a12c` dropped optional ATTDEF fields including width factor while reading DXF. Rerun the regression against the currently merged `7ea4247` revision and update this row with the result. `embedded_mtext` mutation remains unsupported pending linked-layout validation. |
 | AttributeEntity | **Complete** | OCS commit `cf2a9235` and adapter commit `9c6b5c3` make nested ATTRIB records addressable by handle while retaining canonical storage in `Insert.attributes`. Host validation binds tag to a definition in the Insert's block, validates placement/text geometry and style references, keeps owner and definition handles read-only, and preserves embedded MTEXT. `staged_python_attribute_entity_lifecycle_over_real_ipc` passes C/R/E/D/U/I/W/V/P with a real block, ATTDEF and Insert: high-level create/read/transaction edit/delete, parent selection, rendered text, atomic invalid tag/height/owner rejection, edited and deleted DWG/DXF reopen, and three-step undo/redo. `nested_insert_attribute_crud_uses_parent_storage_and_undo` additionally proves the child never becomes an orphan flat entity in the host document. |
 | Hatch | **Complete** | OCS commit `98b56ef6` and adapter commit `a9b5de8` expose solid and patterned Hatches with elevation/normal, complete pattern definitions, pattern controls, style, association state, boundary paths and seed points. Nested tagged boundary edges use the reusable `{kind, value}` adapter form. Host validation requires closed finite loops, validates line/arc/ellipse/polyline/spline payloads and stored pattern lines, resolves associative boundary handles, and preserves gradient and MPOLYGON payloads as explicitly unsupported. `staged_python_hatch_lifecycle_over_real_ipc` passes C/R/E/D/U/I/W/V/P: Python solid creation, patterned boundary edit, live render-model pattern/boundary checks, selection, atomic invalid scale/association/open-loop/unmapped-property rejection, edited and deleted DWG/DXF reopen, post-reopen edits, and three-step undo/redo. |
-| Leader | **Integration-tested / blocked at W by acadrust** | Fields mapped writable: `vertices` (≥2 finite points, not all coincident), `annotation_handle`, `creation_type`, `path_type`, `dimension_style`, `arrow_enabled`, `hookline_enabled`, `hookline_direction`, `text_height`, `text_width`, `normal`, `horizontal_direction`, `block_offset`, `annotation_offset`. Read-only: `origin`, `dimension_gap`, `arrowhead_type`, `arrow_size`, `byblock_color`. Unmapped but preserved on edit: `override_color` (multi-payload `Color` enum the generator cannot express) and the `dwg_unknown_*` fields. Host reference binding validates that `annotation_handle` exists, is not the leader itself, matches `creation_type` (Text/MText, Tolerance, Insert; `NoAnnotation` forbids a handle) and that `dimension_style` exists; nothing is silently defaulted. `staged_python_leader_lifecycle_over_real_ipc` passes C/R/E/D/U/I/V/P against acadrust `7ea4247`: linked Text annotation, path/height/arrow/offset transaction edit with untouched-field preservation, GUI pick grouping (scripted selection stays exact), seven single-edit rejections plus a cross-entity atomic rollback, four-step undo/redo, real render linework, DWG and DXF reopen and re-edit. Erasing a leader also erases its annotation (scene leader grouping); undo restores both. **W blockers (engine, recorded as canary assertions in the test):** (1) the DXF writer never emits group 340, so a DXF save unlinks the annotation; (2) DXF reads drop `annotation_offset` (group 213 is written but not reassembled); (3) DWG R2010+ does not store `text_height`, `text_width` or `hookline_enabled` (acadrust writes them only for R13–R2007 / R13–R14). Not `Complete` until the engine round-trips (1) and (2); (3) needs a decision to document or make read-only. |
+| Leader | **Integration-tested / blocked at W by acadrust** | Fields mapped writable: `vertices` (≥2 finite points, not all coincident), `annotation_handle`, `creation_type`, `path_type`, `dimension_style`, `arrow_enabled`, `hookline_enabled`, `hookline_direction`, `text_height`, `text_width`, `normal`, `horizontal_direction`, `block_offset`, `annotation_offset`. Read-only: `origin`, `dimension_gap`, `arrowhead_type`, `arrow_size`, `byblock_color`. `override_color` is writable through the new generator `Color` form (`{'kind': 'Rgb', 'value': {'r','g','b'}}`, `Index`, `ByLayer`, `ByBlock`, `None`). Unmapped but preserved on edit: the `dwg_unknown_*` fields. Host reference binding validates that `annotation_handle` exists, is not the leader itself, matches `creation_type` (Text/MText, Tolerance, Insert; `NoAnnotation` forbids a handle) and that `dimension_style` exists; nothing is silently defaulted. `staged_python_leader_lifecycle_over_real_ipc` passes C/R/E/D/U/I/V/P against acadrust `7ea4247`: linked Text annotation, path/height/arrow/offset transaction edit with untouched-field preservation, GUI pick grouping (scripted selection stays exact), seven single-edit rejections plus a cross-entity atomic rollback, four-step undo/redo, real render linework, DWG and DXF reopen and re-edit. Erasing a leader also erases its annotation (scene leader grouping); undo restores both. **W blockers (engine, recorded as canary assertions in the test):** (1) the DXF writer never emits group 340, so a DXF save unlinks the annotation; (2) DXF reads drop `annotation_offset` (group 213 is written but not reassembled); (3) DWG R2010+ does not store `text_height`, `text_width` or `hookline_enabled` (acadrust writes them only for R13–R2007 / R13–R14); (4) neither writer stores `override_color`, so it reopens as `ByLayer` in DWG and DXF. Not `Complete` until the engine round-trips (1) and (2); (3) needs a decision to document or make read-only. |
 | MLine | **Complete** | Writable: `vertices` (raw vertex dicts; a script may pass only `position`), `flags` (integer, unknown bits rejected), `justification`, `normal`, `scale_factor`, `style_name`. Read-only: `start_point`, `style_handle`, `style_element_count`. Host validation requires ≥2 finite non-coincident vertices, ≥3 for a closed multiline, a finite nonzero scale and normal, an existing non-empty `MLineStyle`, and per-vertex segments that are either empty or match the style element count. Vertex `direction`/`miter`, segment layout and per-element miter offsets (justification and scale included) are host-derived by `normalize_scripted_mline` on every scripted create or edit, reusing the drawing command's `rebuild_mline_geometry`/`sync_mline_element_parameters`; dash and fill cuts survive an edit unless a vertex moves. `staged_python_mline_lifecycle_over_real_ipc` passes C/R/E/D/U/I/W/V/P: create against the Standard style, a three-vertex/scale/justification transaction edit with untouched-field preservation, corner miter widening and element offsets checked, real `mline_lines` linework before and after DWG and DXF reopen, nine single-edit rejections plus a cross-entity atomic rollback, re-edit after reopen in both formats, deletion, and three-step undo/redo. Known limit: switching to a style with a different element count is rejected until the script also clears the vertices' `segments`; only the rejection is covered by the integration test. |
 | Dimension | **Complete** (all 9 subtypes) | `EntityType::Dimension` wraps a nine-variant enum, so the adapter uses a hand-written flat model (`dimension_model.rs.inc`, wired in through the manifest's `manual_kinds`) and the coverage catalog lists its properties through the policy's `synthetic` section. Python sees `subtype` (fixed at creation), the shared base fields (`text`, `style_name`, `normal`, `text_middle_point`, `attachment_point`, `text_rotation`, `horizontal_direction`, `flip_arrow1/2`, `text_user_positioned`) and only the fields of that subtype; a field from another subtype is rejected, not ignored. `actual_measurement` and the base definition point are host-derived (`normalize_scripted_dimension`, the same recompute grip edits use). Unmapped but preserved: `user_text`, `insertion_point`, `block_name`, version and DWG flags, style overrides in XDATA. Per-subtype status, all verified by `staged_python_dimension_lifecycle_over_real_ipc` (C/R/E/D/U/I/W/V/P; measurement and canvas wires checked for each, DWG and DXF reopen recorded per subtype): Linear (10), Aligned (5), Radius (5), Diameter (10), Angular3Pt (90°), Angular2Ln (90°), Ordinate (5), Arc (5·π/2), LargeRadial (6) — every one creates, reads, derives the right measurement, renders wires, and keeps its measurement through DWG and DXF. Edits (Linear second point/text/attachment, Radius definition point) update the measurement, nine rejection cases plus a cross-entity atomic rollback and three create-time rejections leave the document untouched, and post-reopen re-edit passes in both formats. Not covered: text formatting overrides, arrowheads and other DIMSTYLE overrides stored in XDATA, the anonymous `*D` block. The subtype-specific field meanings for the angular subtypes follow the DXF group-code layout rather than the acadrust convenience constructors. |
 | MultiLeader | Layer-only | Requires nested context and style fixture. |