feat: preserve body history and placed modelling workflows

Record ownership transfers in the timeline so earlier Join/Cut membership,
world placement, machining data and styles survive component moves, edits,
independent copying, undo and reopening. Preserve pending positions in history
snapshots and keep constructor transfers ordered during feature redefinition.

Retain shallow sheet pockets and exact planar intersection islands through
unfold/refold, with depth-aware flat previews and DXF export. Store explicit
3D wire coordinate spaces and migrate known legacy provenance without moving
saved points or analytic fits.

Infer unique eligible cylindrical Emboss targets, align Revolve manipulators
with actual extent geometry, and discard obsolete preview errors after input
correction. Certify constructed and immutable imported face styles using exact
source metadata while preserving legacy face names. Upgrade designs to format10
with bounded validation and geometry-preserving legacy migration.

docs/book/src/guide/files.md

@@ -18,7 +18,11 @@ replaced version is kept as `<file>.bak`. Unsaved changes are autosaved to a rec
 and the next launch offers to recover them. Older design files are upgraded on open, and files
 from a newer version are refused with a message.
 
-Current designs use format 9 for semantic configuration styles, associative free-form offsets
-and explicit cylindrical emboss selections. Older geometry and expressions retain their
-meaning during upgrade; missing new fields use defaults. Association records and occurrence
-paths are bounded and checked before they can alter geometry.
+Current designs use format 10 for recorded body transfers, explicit 3D curve coordinate
+spaces and certified face bindings, alongside semantic configuration styles, associative
+free-form offsets and cylindrical emboss selections. Older ownership maps, geometry and
+expressions retain their saved meaning. Legacy 3D curves with retained associations receive
+their producer's coordinate-space marker without changing any saved points; detached curves
+retain world coordinates. A lost cross-component association refreshed by an older build may
+need an explicit relink or refresh when its source returns. Loading never guesses a numerical
+correction. Association records, coordinate arrays and placements are bounded and checked.

docs/book/src/guide/sheet-metal.md

@@ -38,3 +38,18 @@ Cuts can leave separate material pieces, including the centre of a ring cut. The
 remain one logical sheet group through Unfold / Refold and export as separate flat outlines.
 Large profiles that exceed the geometry processing budget report an error instead of
 exporting a partial outline.
+
+Parallel, untapered extrude cuts also preserve shallow pockets through Unfold / Refold.
+The pocket floor and side walls remain solid geometry; overlapping cuts from opposite sides
+become a through hole wherever they remove the whole thickness. Flat-pattern JSON lists
+`pockets` with their side, depth and bottom/top thickness coordinates in millimetres.
+DXF pocket boundaries use `POCKET_BOTTOM_Z…_TO_…_MM`, `POCKET_TOP_Z…_TO_…_MM`, or
+`POCKET_INTERNAL_Z…_TO_…_MM` layers. These are machining operations, so do not treat every
+pocket layer as a through-cut contour when importing the drawing into a CAM tool.
+
+Extrude Intersect on a straight base or an unfolded sheet retains the exact planar material,
+including interior holes and detached islands. A completely empty intersection removes the
+sheet and its metadata together. Pocket profiles can move with planar panels when forming,
+but a pocket crossing a bend zone cannot yet be refolded. Machining folded bend material,
+tapered sheet cuts and other unsupported 3D sheet Cut/Intersect operations report an error before changing
+the design; they cannot silently restore removed material during a later sheet rebuild.

docs/book/src/guide/sketching.md

@@ -29,6 +29,18 @@ Smooth open offsets can be offset again, including bounded refinement after a so
 A closed offset uses a natural cubic spline whose seam can have different end tangents;
 offsetting that result again is refused when the seam has no unique normal.
 
+Enable **3D Sketch** in the Sketch Palette to draw lines, fit splines and points off the plane.
+New 3D geometry follows its sketch's component placement, including the selected occurrence
+and pending position changes. Click a drawn fit point to show its move triad; its arrows move
+along world X, Y and Z. Scripts also supply world coordinates to `sketch.line3d`,
+`sketch.spline3d`, `sketch.point3d` and `sketch.move3d`. Activate the desired occurrence before
+editing an explicit sketch belonging to a component with multiple placements.
+
+Older drawn or detached 3D wires keep their saved world positions. Included and surface-linked
+wires with an explicit component marker keep that meaning after the link is broken. Old files
+whose links became lost after an incorrectly scoped cross-component refresh may require a
+fresh link once the source is available; their stored point values are preserved on opening.
+
 ## Constraints and dimensions
 
 The solver is SolveCraft's own (damped Gauss–Newton with degree-of-freedom analysis). Constraints: