Complete MLine host model coverage

Maps vertices, flags, justification, normal, scale and style with host
validation and MLineStyle binding. The host recomputes vertex direction,
miter and element parameters on scripted create/edit, so scripts only supply
positions. staged_python_mline_lifecycle_over_real_ipc passes the full gate
including DWG and DXF reopen.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

docs/plugin-host-model-completion-plan.md

@@ -7,13 +7,13 @@ Build a general Python document model over the OCS host API for all **43 canvas
 As of 20 September 2026, the working branch is `plugin/host-model-api` at
 `a8dd3640` plus the Leader increment, published as draft PR
 [#1391](https://github.com/HakanSeven12/OpenCADStudio/pull/1391). Host API is
-v7. The Python feature has explicit writes for **23 of 43** canvas kinds: 22
-are creatable and `Insert` remains update-only. This is **not** 23 completed
-kinds: Tolerance, Shape, AttributeEntity and Hatch pass every completion gate.
+v7. The Python feature has explicit writes for **24 of 43** canvas kinds: 23
+are creatable and `Insert` remains update-only. This is **not** 24 completed
+kinds: Tolerance, Shape, AttributeEntity, Hatch and MLine pass every completion gate.
 AttributeDefinition passes its host and real IPC lifecycle but remains short of
 `Complete` because the previously pinned CAD codec dropped optional ATTDEF
 fields during DXF reads; revalidate that blocker against the current
-`acadrust` revision `7ea4247`. Leader is mapped and integration-tested but blocked at W by three acadrust persistence gaps (see the ledger). The other 20 canvas kinds have only `layer`
+`acadrust` revision `7ea4247`. Leader is mapped and integration-tested but blocked at W by three acadrust persistence gaps (see the ledger). The other 19 canvas kinds have only `layer`
 writes through the document model. All 43 have raw typed snapshots. There are
 three internal records and two opaque fallbacks outside the 43 canvas kinds.
 
@@ -123,7 +123,7 @@ The last five may require new engine capabilities rather than only Python conver
 
 ## Handoff start point
 
-Continue with **MLine** (queue item 2). Leader is done except for its W
+Continue with **Dimension** (queue item 3; track each subtype separately). Leader is done except for its W
 gate; when the engine writes DXF group 340, reads group 213 and the DWG
 R2010+ text-size question is decided, flip the canary assertions in
 `staged_python_leader_lifecycle_over_real_ipc` and mark it `Complete`.
@@ -158,3 +158,4 @@ exact queue above and update statuses with evidence after each increment.
 - Completed `Hatch` with full solid/pattern definitions and typed nested boundary paths. The adapter generator now handles single-payload tagged enums as `{kind, value}` dictionaries, which covers every Hatch edge variant and is reusable by later nested entity models. Unknown adapter properties are rejected instead of being silently ignored.
 - `staged_python_hatch_lifecycle_over_real_ipc` passes C/R/E/D/U/I/W/V/P with closed line-loop fixtures: solid creation, conversion to a stored-line pattern, boundary replacement, selection and live render-cache checks, atomic invalid scale/association/open-loop/unmapped-payload rejection, edited/deleted DWG and DXF reopen, post-reopen edits, and three-step undo/redo. Hatch is **Complete**; the queue now continues with `Leader`.
 - Mapped `Leader` (host validation and reference binding in `entity_coverage.rs`, policy/build.rs/manifest entries, adapter count 23). `staged_python_leader_lifecycle_over_real_ipc` passes C/R/E/D/U/I/V/P through the real runner. W is blocked by acadrust: the DXF writer omits the annotation handle (340), DXF reads lose `annotation_offset` (213), and DWG R2010+ does not store text size or hookline flag. Each gap is pinned by a canary assertion so it fails loudly once fixed. The queue now continues with `MLine`.
+- Completed `MLine`. Host validation and style binding live in `ocs_plugin_api`; derived vertex geometry and element parameters are recomputed by the host (`normalize_scripted_mline`) on scripted create/edit, so scripts supply positions only. The adapter maps `flags` as an integer through a manifest override because the generator cannot classify acadrust's serde-newtype `MLineFlags`. `staged_python_mline_lifecycle_over_real_ipc` passes C/R/E/D/U/I/W/V/P with DWG and DXF reopen. The queue now continues with `Dimension`.

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

@@ -1,6 +1,6 @@
 # OCS canvas kind coverage ledger
 
-Use with [the completion plan](plugin-host-model-completion-plan.md). This ledger is current as of 20 September 2026: **23 of 43 canvas kinds have explicit geometry writes** (22 creatable, plus update-only `Insert`), **4 kinds are complete**, and 20 remain layer-only. `Mapped` means at least one non-layer field is exposed for Python writes; it does **not** mean the kind passes the completion gate. `Update-only` means Python creation is unavailable. `Layer-only` means raw inspection and canvas layer edits exist, but geometry is not mapped. Record actual evidence or a blocking issue before changing any status to `Complete`.
+Use with [the completion plan](plugin-host-model-completion-plan.md). This ledger is current as of 20 September 2026: **24 of 43 canvas kinds have explicit geometry writes** (23 creatable, plus update-only `Insert`), **5 kinds are complete**, and 19 remain layer-only. `Mapped` means at least one non-layer field is exposed for Python writes; it does **not** mean the kind passes the completion gate. `Update-only` means Python creation is unavailable. `Layer-only` means raw inspection and canvas layer edits exist, but geometry is not mapped. Record actual evidence or a blocking issue before changing any status to `Complete`.
 
 Completion gate codes: **C** = create through Python document model; **R** = read; **E** = edit defining geometry and another property; **D** = delete; **U** = undo/redo and atomic failure; **I** = real IPC plus GUI/canvas pick or observable behavior; **W** = DWG and DXF save/reopen; **V** = invalid-input checks and untouched-field/reference preservation; **P** = build and load the in-tree bundled plugin with a manifest matching the host toolchain and acadrust source. A kind is `Complete` only when **C/R/E/D/U/I/W/V/P** all pass and its property catalog matches implementation. `Blocked` requires a specific dependency or failing fixture.
 
@@ -29,7 +29,7 @@ Completion gate codes: **C** = create through Python document model; **R** = rea
 | 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. |
-| MLine | Layer-only | Requires valid style and vertex fixture. |
+| 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 | Layer-only | Track individual dimension subtypes. |
 | MultiLeader | Layer-only | Requires nested context and style fixture. |
 | Table | Layer-only | Requires table style and cell fixture. |

docs/plugin-host-model.md

@@ -35,7 +35,7 @@ attached attribute and sequence records. Those fields report `transaction_geomet
 catalog. All 43 canvas kinds also support nonempty `layer` changes through
 the same undoable transaction; internal and opaque variants remain read-only
 through the document model. The adapter accepts only `layer` patches for
-canvas kinds outside its 23 geometry converters. Other writable properties
+canvas kinds outside its 24 geometry converters. Other writable properties
 still report `type_conversion_only`; broader CAD range and cross-property
 checks remain outstanding.
 The host's `entity_snapshot` helper serializes any typed entity as a detached
@@ -91,7 +91,7 @@ Input tokens are bound to the drawing tab that requested the pick. Polling a
 token from another tab returns no result and does not consume it.
 
 Python `doc.entities[handle]` returns a descriptor for every entity. For kinds
-outside the 23-kind generated schema it contains only handle, kind, and layer;
+outside the 24-kind generated schema it contains only handle, kind, and layer;
 `layer` is editable on canvas kinds. `doc.coverage()` enumerates the
 catalog; `doc.coverage("Line")` and `line.coverage` return one entry. For
 covered kinds, the coverage object lists actual readable and editable