Merge PR #1028: add document API with atomic edits

Add the typed document facade and plugin IPC adapter. Prepare bulk edits
before mutation, preserve undo and dirty state, keep profile elevations,
validate numeric inputs and session bindings, and generate Python constructors
with typed results.

Reuse existing entity transforms and profile conversion. Compute mass
properties and closed-surface bounds in cadkernel; pin its main revision
6a5e6fc2822f6af6b2611cd605b44437b35158f0. Keep plugin API metadata at version 6.

Validation: 646 native application tests, 597 kernel tests, 12 document API
tests, 91 plugin API tests, 3 Python tests, default/IPC feature builds and
wasm32 check passed.

crates/ocs_doc_api/src/gen/ops_gen.rs

@@ -0,0 +1,102 @@
+// HAND-MAINTAINED wire vocabulary (the Operation enum). This file is NOT derived
+// from spec/entities.toml by build.rs — the enum is the canonical append-only
+// wire vocabulary; the spec's `op` names must each map to a variant here
+// (enforced by a test). Append new variants at the END only (bincode discriminant
+// stability). Do NOT reorder or remove variants.
+
+use serde::{Deserialize, Serialize};
+
+use crate::id::ObjectId;
+use crate::ops::{
+    AttributeDefinitionSpec, BoolOp, Curve2Spec, DimensionAngularSpec, DimensionRadialSpec,
+    DimensionSpec, EntitySpec, HatchSpec, InsertSpec, MTextSpec, PlacementSpec, RasterImageSpec,
+    SolidPrimitive, TableSpec, TextSpec, ViewportSpec,
+};
+
+/// A typed write operation. Each variant is ONE atomic host call = one
+/// undo step. Append new variants at the END only.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[non_exhaustive]
+pub enum Operation {
+    // construction
+    CreateSolid(SolidPrimitive),
+    CreateCurve(Curve2Spec),
+    Extrude {
+        profile: ObjectId,
+        direction: [f64; 3],
+    },
+    Revolve {
+        profile: ObjectId,
+        axis: ([f64; 3], [f64; 3]),
+        angle: f64,
+    },
+    // modification
+    Transform {
+        id: ObjectId,
+        placement: PlacementSpec,
+    },
+    SolidBoolean {
+        op: BoolOp,
+        a: ObjectId,
+        b: ObjectId,
+        erase_sources: bool,
+    },
+    AddVertex {
+        id: ObjectId,
+        at: usize,
+        point: [f64; 3],
+    },
+    Delete {
+        id: ObjectId,
+    },
+    // Bulk ops (single op, upfront-validation all-or-nothing — NOT a transaction, §5.3)
+    CreateMany(Vec<EntitySpec>),
+    TransformMany {
+        ids: Vec<ObjectId>,
+        placement: PlacementSpec,
+    },
+    DeleteMany(Vec<ObjectId>),
+    // containers
+    CreateInsert(InsertSpec),
+    // paper-space
+    CreateViewport(ViewportSpec),
+    // annotations
+    CreateText(TextSpec),
+    CreateMText(MTextSpec),
+    SetTextContent {
+        id: ObjectId,
+        value: String,
+    },
+    // hatch
+    CreateHatch(HatchSpec),
+    // dimensions
+    CreateDimensionLinear(DimensionSpec),
+    // attributes
+    SetAttribute {
+        id: ObjectId,
+        tag: String,
+        value: String,
+    },
+    // viewport view
+    SetViewportView {
+        id: ObjectId,
+        view_target: [f64; 3],
+        view_height: f64,
+    },
+    // media
+    CreateRasterImage(RasterImageSpec),
+    // multi-profile solid
+    Loft {
+        profiles: Vec<ObjectId>,
+    },
+    // dimension sub-types
+    CreateDimensionRadius(DimensionRadialSpec),
+    CreateDimensionDiameter(DimensionRadialSpec),
+    CreateDimensionAngular(DimensionAngularSpec),
+    // attribute definitions
+    CreateAttributeDefinition(AttributeDefinitionSpec),
+    // tables
+    CreateTable(TableSpec),
+    // dimension sub-types (2-line angular)
+    CreateDimensionAngular2Ln(DimensionAngularSpec),
+}