M0: engine command registry, file formats, view math and CPU renderer

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/io/Cargo.toml

@@ -1,8 +1,15 @@
 [package]
 name = "solvecraft-io"
+description = "SolveCraft file formats: designs (JSON), STL, OBJ and STEP export"
 version.workspace = true
 edition.workspace = true
 license.workspace = true
 
 [lints]
 workspace = true
+
+[dependencies]
+solvecraft-geom = { workspace = true }
+solvecraft-kernel = { workspace = true }
+solvecraft-doc = { workspace = true }
+thiserror = { workspace = true }