Reconstruct constant-section meshes as parametric solids

docs/book/src/guide/files.md

@@ -13,6 +13,20 @@ Opening a STEP or IGES file creates a design with the file's bodies as a base fe
 inserting one adds them to the current design. Later features build on them. Mesh bodies render,
 measure, move and export, but solid features need B-rep bodies.
 
+For closed mechanical meshes with a constant cross-section, use **Mesh → Modify →
+Convert Mesh**. Select the mesh body and set the fitting tolerance. The conversion
+rebuilds planar faces and circular through-walls, replacing the mesh with a solid
+that accepts solid modeling operations. The imported triangles remain embedded
+upstream: changing their scale, undoing the conversion or reopening the design
+rebuilds the result through the timeline. Double-click the conversion to edit its
+tolerance or source body.
+
+The tolerance bounds circular reconstruction against the original chords. Coarse
+polygons remain polygons when rounding would exceed it. Open/nonmanifold meshes,
+tapers, stepped parts and organic scans are refused by this first reconstruction
+method; it does not silently substitute a faceted solid. Conversion currently
+accepts at most 50,000 triangles and a bounded number of boundary segments.
+
 Saves are atomic: a crash at any moment leaves either the old file or the new one, and the
 replaced version is kept as `<file>.bak`. Unsaved changes are autosaved to a recovery folder,
 and the next launch offers to recover them. Older design files are upgraded on open, and files

docs/parity.md

@@ -2,9 +2,9 @@
 
 Generated by `cargo xtask parity` from `xtask/data/fusion-catalog.tsv` (the toolbar commands of Fusion's Design workspace, ids and names only) and the live command registry (`solvecraft-cli commands`). A command counts as live when SolidCraft registers the same command id. This measures breadth, not depth; see ROADMAP.md and docs/oracle.md for depth.
 
-**In scope (SOLID, SKETCH, ASSEMBLY, SHEET METAL, PLASTIC enclosure subset): 335 / 541 commands live (62%).** SOLID + SKETCH: 188 / 291 (65%). Registered commands: 311.
+**In scope (SOLID, SKETCH, ASSEMBLY, SHEET METAL, PLASTIC enclosure subset): 335 / 541 commands live (62%).** SOLID + SKETCH: 188 / 291 (65%). Registered commands: 314.
 
-Deferred until further notice (not in the in-scope figure): MESH, FORM, SURFACE beyond what solids need, PCB, render, animation, simulation, manufacture, drawings, MANAGE, UTILITIES and the rest of PLASTIC. All Design tabs together: 630 / 1175 (54%).
+Deferred until further notice (not in the in-scope figure): MESH, FORM, SURFACE beyond what solids need, PCB, render, animation, simulation, manufacture, drawings, MANAGE, UTILITIES and the rest of PLASTIC. All Design tabs together: 631 / 1175 (54%).
 
 | Tab | Panel | Live | Total | % |
 |---|---|---:|---:|---:|
@@ -64,7 +64,7 @@ Deferred until further notice (not in the in-scope figure): MESH, FORM, SURFACE
 | SURFACE | POSITION | 2 | 2 | 100% |
 | MESH | CREATE | 2 | 5 | 40% |
 | MESH | PREPARE | 0 | 4 | 0% |
-| MESH | MODIFY | 6 | 30 | 20% |
+| MESH | MODIFY | 7 | 30 | 23% |
 | MESH | ASSEMBLE | 12 | 21 | 57% |
 | MESH | CONFIGURE | 3 | 3 | 100% |
 | MESH | CONSTRUCT | 19 | 20 | 95% |