Design tab: translatable offer, one vocabulary, reports in the status line

- Offer table: user-facing strings carry the L() marker so xgettext
  extracts them; DesignOffer.hpp, DesignSketchTool.cpp and
  SketchInlineEditor.cpp are listed in localization/i18n/list.txt.
- Offer: model-mode Constrain sits in the same row as the sketch one;
  Interference is wired; Rib shows its R key; a verb that accepts the
  selection but is blocked by the document stays greyed with its reason
  instead of vanishing from the submenu; one refusal wording per verb.
- Extrude infers Join when the profile touches a solid (new
  CadDocument::body_touching_sketch) and on face push/pull; New body in
  free space. Revolve/Sweep/Loft/Boolean use the same result words.
- Interference and volume/area reports go to the status line in mm3/mm2
  instead of modal dialogs; Delete Body no longer asks (it is undoable).
- New feature names match the card header ("Extrude 3"), translated;
  "Coordinate system", "Angle (°)", center/color spelling, translated
  face and length readouts, slot hints say width.
- CAD gizmos in Prepare are selectable only with the CAD feature on; the
  sketch auto-close setting is stored per design.
- Docs: confirm/cancel rules, enabling the feature and MCP in
  design_tab.md; drift-only right-click in interaction-model.md; the
  portability note rewritten to describe the integration as it is.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QK4VgguuCAk2hZLWgcjJb9

scripts/CAD/check-gui-context-menu.py

@@ -95,7 +95,8 @@ def load_table():
         f.append(cur.strip())
         if len(f) < 12:
             continue
-        lit = lambda s: None if s == "nullptr" else s.strip('"')
+        # User-facing fields are wrapped in the L("...") gettext marker; strip it.
+        lit = lambda s: None if s == "nullptr" else re.sub(r'^L\((.*)\)$', r'\1', s).strip('"')
         out.append({"id": lit(f[0]), "name": lit(f[1]), "row": int(f[2]), "key": lit(f[3]),
                     "action": lit(f[4]), "accepts": int(f[6].rstrip("u"), 0),
                     "need_bodies": int(f[7]), "need_sketches": int(f[8]),