Add build system for native applications

- PyInstaller spec file for cross-platform builds
- Build scripts for Linux/macOS (build.sh) and Windows (build.bat)
- requirements.txt with all dependencies
- Updated README with build and installation instructions
- Support for creating standalone executables for all platforms

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.claude/settings.local.json

@@ -0,0 +1,9 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(python:*)"
+    ],
+    "deny": [],
+    "ask": []
+  }
+}