Remove macOS and Windows references from user-facing docs

Strip all macOS/Windows/WSL2 mentions from README.md and SERVICES.md.
Platform status, GPU support, permission examples, and config paths
now reflect Linux-only. TODO.md retains references as future roadmap tracking.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

README.md

@@ -11,8 +11,6 @@
 
 **Platform Status:**
 - **Linux**: Stable and actively developed
-- **macOS**: Planned for a future release
-- **Windows (WSL2)**: Planned for a future release
 
 ## Key Features