Sweep: orientation, twist and end scale (#1269)

Part of #771 and #772. solid.sweep and surface.sweep take orientation (perpendicular, parallel or a direction), twist (up to 4 turns) and end scale (0.01 to 100), applied about the profile's normal through the path's start; default options run the old sweep, so existing sweeps are unchanged. New fields are optional, left out when unset and noted under format 21; twist and scale are model parameters. Both sweep dialogs get Orientation, Twist and End Scale rows; labels in every catalog. Checked on main + this branch: cargo check --workspace, kernel/engine/UI sweep tests, the doc suite and the robustness goldens.

ROADMAP.md

@@ -51,7 +51,7 @@ PCB / Package, Render, Animation, Simulation, Manufacture/CAM, Drawings.
 | M5 | Persistent naming of faces and edges (docs/book/src/dev/naming.md): faces named from their exact kernel-reported history (sketch curve sides, caps, revolve sections, primitive sides, blends, shell inner walls, pattern/mirror copies; split pieces told apart by the faces around them, lumps of a cut body named after their faces), edges by their faces; fillets/chamfers, sketches on faces, shell/draft/offset/replace faces, hole placements, joint origins and face appearances resolve by name first and warn when the entity split or vanished: done. sheet metal edges by base sketch line and flange side, shell inner faces, sweep and loft roles: done. kernel-reported face history: done (merged faces answer to every name; operations without history yet fall back to geometric names, flagged unverified; format 14 keeps older designs' geometric names). Left: history through sheet metal, plastic, surface and emboss features; FaceSource certificates through history | in progress | 20 |
 | M6 | UI depth: selection feedback and origin (done), timeline editing (done: hover and selection highlight modifier faces, including fillets and chamfers; edit feature, history marker drag, dependency-checked single and multi-item reorder, suppress, rename, delete with dependents, re-resolved references; redefining selections refreshes persistent edge/face references while retaining feature identity and dimension names; optional compact named left feature history with rollback bar, multi-selection and persistent folders above the parts browser), right-docked dialogs (done), live previews for every feature dialog (done), keyboard-first commands with on-canvas value boxes and sketch inline dimensions (done), drag manipulators with automatic join/cut (done: extrude incl. two sides, fillet, shell, hole depth, move, pattern spacing, revolve rotator; taper handle open), dark theme (done), right-click menu with Repeat (done), measure tool (done), section analysis (done), selection filter (done), drag-solve of sketch points (done); appearance controls now preserve body/face/component targeting, named transparent looks, reuse/search and override removal; preferences | in progress | 6 |
 | M7 | Thin extrude (walls along open or closed curves: centre, inside, outside or two sides; mitred corners, crossing walls joined; #721), sweep, loft (incl. to a point), rib and web (to next / depth), emboss (planar faces and exact radial emboss/deboss of bounded orthogonal profiles on complete exterior cylinders/sleeves), thread (cosmetic, and modelled M3–M20 outside and inside: the ISO profile screwed in as a faceted cut), coil (smooth B-spline helical walls), pipe, pattern on path, patterns of bodies and components, replace face (parallel), align, remove, feature copy/paste: done. Unique eligible cylindrical targets are inferred for new Emboss features. Left: general curved-face emboss and exact (unfaceted) modelled threads | in progress | 12 |
-| M8 | Surface workspace (#772). Done: Patch (sketch regions; edge loops filled G0), Stitch, Thicken (planes and cylinders), Extend (straight edges of planar surfaces), Trim (by a plane or a face), Delete Face (healing), Boundary Fill, zebra/draft/curvature-map analysis. Proposed, in order: surface Extrude/Revolve/Sweep/Loft from open and closed curves (#757), Offset surface (#758), Unstitch and Reverse Normal (#766), Delete Face without healing (#768); Extend curved faces and edges (#760), mutual trim and trim by projected curves (#767), Untrim (#761), Thicken every surface kind (#765); Ruled (#762), Boundary surface and curve networks with G0/G1/G2 (#763), Patch with G1/G2 and general loops (#759), Blend surface (#764), sweep rails, twist and scale (#771, loft rails #201), fillet between surface bodies (#769); continuity analysis, surface curvature combs and isocurves (#770) | deferred | — |
+| M8 | Surface workspace (#772). Done: Patch (sketch regions; edge loops filled G0), Stitch, Thicken (planes and cylinders), Extend (straight edges of planar surfaces), Trim (by a plane or a face), Delete Face (healing), Boundary Fill, zebra/draft/curvature-map analysis. Proposed, in order: surface Extrude/Revolve/Sweep/Loft from open and closed curves (#757), Offset surface (#758), Unstitch and Reverse Normal (#766), Delete Face without healing (#768); Extend curved faces and edges (#760), mutual trim and trim by projected curves (#767), Untrim (#761), Thicken every surface kind (#765); Ruled (#762), Boundary surface and curve networks with G0/G1/G2 (#763), Patch with G1/G2 and general loops (#759), Blend surface (#764), sweep guide rails and two-rail sweeps (#771; orientation, twist and end scale done; loft rails #201), fillet between surface bodies (#769); continuity analysis, surface curvature combs and isocurves (#770) | deferred | — |
 | M9 | Components and assemblies: New Component / Create Components from Bodies, active component, per-component origin/bodies/sketches/timeline entries, occurrences with transforms, Copy/Paste vs Paste New, nested Browser tree with visibility and isolate; Ground, Move/Copy of occurrences, joints (rigid, revolute, slider, cylindrical, pin-slot, planar, ball) by joint origins with limits and Drive Joints, closed kinematic loops (four-bar, slider-crank: the loop's other joints follow the driven one on its branch, and driving stops where a loop can no longer close), As-built Joint, Rigid Group, Contact Sets (driving and motion studies stop where bodies in a set would pass through each other), Motion Study (joint values keyed along a timeline, playback, export of occurrence positions as JSON/CSV), Exploded views (automatic or by hand, shown without changing placements); interference, per-component physical properties; STEP with assembly structure; URDF export for robot simulators (links with meshes, mass and inertia; joint chains whose values match Drive Joints; docs/urdf.md). Physical properties now measure material-aware component/occurrence placements, descendants and repeated instances, including pending moves and body reassignment offsets; contact geometry and automatic exploded centres respect those offsets. Groundwork done: component tree, occurrences with transforms (instances, Paste New), world placement, active component as authoring frame, ground, Capture/Revert Position, moving bodies and sketches. UI: ASSEMBLE panel dialogs for New Component, Joint (snaps on faces, edges, circles and vertices; animated motion preview; offsets, flip, limits), As-built Joint, Joint Origin, Rigid Group, Drive Joints (live slider), Motion Link and Interference (overlaps shown red); joints in the timeline and the Browser | in progress | 32 |
 | M10 | Sheet metal: flange (base, edge, contour), hem, unfold/refold, convert, flat pattern + DXF, rules: done. PLASTIC enclosure subset: Boss, Rib, Web, Lip/Groove, Snap Fit, Rest, Plastic Rules (library, edit, assign; rule draft and clearance as feature defaults): done, tested against hand-computed geometry. UI: SHEET METAL and PLASTIC tabs in Fusion's layout with dialogs (live preview, Edit Feature, pre-selection) for Flange, Hem, Unfold/Refold, Convert, Sheet Metal Rules, Create Flat Pattern (flat view with bend lines, bend table CSV/JSON and DXF export with exact circle/arc/line cutouts), Boss, Lip/Groove, Snap Fit, Rest, Manage and Assign Plastic Rules; Fold (bend along a sketch line); flanges meeting at a corner closed at any angle with the rule's gap; edge flanges with their own angle and height per edge in one feature; corner reliefs (notch, round, rectangular, tear) chosen by the rule; Convert to Sheet Metal from a solid or shelled body by its bend edges (flat faces, sharp bends) | in progress | 36 |
 | M11 | 2D drawings | deferred | — |
@@ -336,6 +336,9 @@ retain their saved two-finger scroll preference; camera motion is available thro
   and conics; analytic trim/break also sees free-form cutters. Free-form curves cut at a tangent
   touch (no clean crossing) enter that profile as polylines.
   Sweeps along 3D sketch curves follow their polyline (smooth walls when the path is smooth).
+  A sweep with a twist, an end scale or a parallel or direction orientation (#771) follows its
+  path that way too, even along sketch lines and arcs: B-spline walls through stations, ruled
+  walls through denser stations where the path has corners or the profile has holes.
 - Extend intersects exact ellipses and rational/high-degree splines without moving the line or
   circular support. Associative free-form offsets have a whole-span 0.002 mm normal-distance
   certificate and refine within bounded node limits while retaining existing IDs.