chore: rename H7CAD to Open CAD Studio

Joining the OpenAEC Foundation (open-aec.com). Crate/struct become
OpenCADStudio, user-facing strings use the spaced "Open CAD Studio"
form, repo URLs point to HakanSeven12/open-cad-studio. Logo (window
icon + assets/logo.svg) redrawn with OCS initials. Drop examples/
binaries — unused.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/snap/mod.rs

@@ -1,4 +1,4 @@
-//! H7CAD-style object snap (OSNAP) engine.
+//! OpenCADStudio-style object snap (OSNAP) engine.
 //!
 //! Implemented modes:
 //!   Endpoint, Midpoint, Center, Node, Quadrant, Intersection,
@@ -13,7 +13,7 @@ use crate::ui::overlay::CROSSHAIR_ARM;
 
 // ── Snap type ─────────────────────────────────────────────────────────────
 
-/// Every OSNAP mode — mirrors the H7CAD list.
+/// Every OSNAP mode — mirrors the OpenCADStudio list.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum SnapType {
     Endpoint,