Components are frames (user bug #4)

What a component holds moves with its occurrence, and picks in the world land in the
component's frame:
- Sketches and construction planes show where their component is placed (free move, joint
  drive, Capture Position); sketch.inspect reports sketch points in the world.
- frames.rs maps a command's world picks into the frame of the body they lie on (through the
  inverse of its placement: a moved component or a pasted instance), points that make new
  geometry into the active component's frame, and directions with them; instance body names
  ("Body1 (Pin:2)") become the component's body. Fillet/chamfer edges, shell/offset/draft
  faces, face extrude/revolve, sketch on face, holes, sheet metal and plastic picks, primitives,
  appearance faces, analyses. Once per command (not again for commands run by commands); the
  active-frame fallback stays for commands without a table. Nothing changes while every
  placement is the identity.
- component.move_bodies keeps a body where it is in the world (Document.body_offsets: from the
  new component's frame to the one it was made in; renames and deleted components follow).
- The UI reads the placed model (Session::world_state) for display, picking, sketch editing and
  dialogs; live previews use it once anything is placed.
Tests (engine): sketches and construction planes move (and turn) with the component; world
picks fillet, sketch, hole and make boxes in a moved component; a pick on a pasted instance;
move_bodies keeps the world place there and back; a sketch on a face follows a Move feature.
QA's s34 now runs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL

crates/ui-egui/tests/scenarios.rs

@@ -51,6 +51,7 @@ scenarios!(
     s25_autosave_recovery,
     s27_move_triad,
     s33_move_x_arrow,
+    s34_component_move_carries_sketches,
 );
 
 /// Scenarios written ahead of their fixes or features (the user's open bugs): run with
@@ -68,6 +69,5 @@ macro_rules! pending {
 pending!(
     s31_sketch_on_face_projects: "user bug: a sketch on a face projects its loops as reference (solvecraft-sketch)",
     s32_cut_in_active_component: "user bug: a cut in the active component leaves others alone (solvecraft-params)",
-    s34_component_move_carries_sketches: "user bug: moving a component carries its sketches (solvecraft-repo)",
     s30_pattern_a_hole: "the dialog sends the hole as a feature; the engine's pattern of a blind hole cuts too little (one hole short)",
 );