ocs_doc_api: update docs + fix review-drift findings

- lib.rs: export all 14 facade handles (add ArcCurve/Ellipse/Spline/Ray/XLine/Text/
  MText/Dimension + Circle) — public surface matches collection return types.
- build.rs: fix step-1 comment (enums are hand-maintained, not 'regenerated');
  generic_reference_md: Clone (not Copy) + full 14-handle list (was stale 6).
- ops.rs/query.rs: correct 'hand-maintained' module doc comments (were 'GENERATED').
- layouts.json: extend to all 22 Operation + 12 Query variants (was stale phase-1).
- binding_schema.json regenerated (complete layouts + derived handles).
- generate.py: inject 'id': self.id for SetTextContent/SetAttribute/SetViewportView/
  Transform/Delete/AddVertex (was malformed id-less payloads); _apply_op/_apply_query
  accept want=None; extend PY_TYPES (String/&str/Vec returns/new handles).
- README.md: Clone (not Copy) + full scope (2D curves, annotations, containers,
  viewports, media) replacing stale 'Not yet' list.
- Plan (.kilo): mark implemented & published; pointer to live crate docs.

crates/ocs_doc_api/src/lib.rs

@@ -46,8 +46,9 @@ pub use revision::GeometryRevision;
 
 pub use envelope::{DocApiEnvelope, EnvelopeBody, OpOutcome, Receipt};
 pub use facade::{
-    CurveCollection, DocApi, Document, Entity, EntityCollection, HasId, Line, OpGroup, Point,
-    Polyline, QueryBatch, QueryResults, Solid, SolidCollection,
+    ArcCurve, Circle, CurveCollection, Dimension, DocApi, Document, Ellipse, Entity,
+    EntityCollection, HasId, Line, MText, OpGroup, Point, Polyline, QueryBatch, QueryResults, Ray,
+    Solid, SolidCollection, Spline, Text, XLine,
 };
 pub use ops::{BoolOp, Curve2Spec, EntitySpec, Operation, PlacementSpec, SolidPrimitive};
 pub use query::{Aabb, EntityView, Query, QueryResult};