chore(release): bump to 0.4.0

Fix repo URLs to canonical HakanSeven12/OpenCADStudio casing.

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

ROADMAP.md

@@ -91,7 +91,7 @@ decode until **first render** (per-handle lazy `OnceCell`).
 ### 1.7 File-hash cache (warm re-open)
 
 When re-opening the same file (`(path, mtime, size)` key) keep a disk
-snapshot of `CadDocument` + `DerivedCaches` (e.g. `~/.cache/open-cad-studio/`). Skip
+snapshot of `CadDocument` + `DerivedCaches` (e.g. `~/.cache/OpenCADStudio/`). Skip
 DWG parse entirely. **Win:** most-recently-opened file goes from 1-2 s to
 sub-100 ms.