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/modules/home/draw/arc.rs

@@ -1,4 +1,4 @@
-// Arc tool — ribbon dropdown + all H7CAD arc creation methods.
+// Arc tool — ribbon dropdown + all OpenCADStudio arc creation methods.
 //
 // Methods:
 //   ARC     — Center, Start, End    (CSE — default)

src/modules/home/draw/circle.rs

@@ -1,4 +1,4 @@
-// Circle tool — ribbon dropdown + all H7CAD circle creation methods.
+// Circle tool — ribbon dropdown + all OpenCADStudio circle creation methods.
 //
 // Methods:
 //   CIRCLE     — Center, Radius   (default)

src/modules/home/draw/ellipse.rs

@@ -1,4 +1,4 @@
-// Ellipse tool — ribbon dropdown + all H7CAD ellipse creation methods.
+// Ellipse tool — ribbon dropdown + all OpenCADStudio ellipse creation methods.
 //
 // Commands:
 //   ELLIPSE      — Center, Axes  (center → major endpoint → minor distance)

src/modules/home/draw/hatch.rs

@@ -1,11 +1,11 @@
-// Hatch/Gradient/Boundary commands — H7CAD Home > Draw > Hatch dropdown.
+// Hatch/Gradient/Boundary commands — OpenCADStudio Home > Draw > Hatch dropdown.
 //
 // Commands:
 //   HATCH    — ANSI31: 45° hatch lines (pick inside or type S for manual)
 //   GRADIENT — Linear gradient fill (pick inside or type S for manual)
 //   BOUNDARY — Traces the enclosing boundary as a closed LwPolyline
 //
-// Primary workflow (matches H7CAD):
+// Primary workflow (matches OpenCADStudio):
 //   Click a point INSIDE a closed region → boundary auto-detected.
 //   Type "S" to switch to manual vertex-picking mode (HATCH/GRADIENT only).
 

src/modules/home/draw/line.rs

@@ -1,6 +1,6 @@
 // Line tool — ribbon definition + interactive command.
 //
-// Command:  LINE — H7CAD behaviour:
+// Command:  LINE — OpenCADStudio behaviour:
 //   1. First click  → stores start point, prompts for next point
 //   2. Each further click → immediately commits an acadrust::Line entity
 //      (start→end) to the document; end becomes the new start point