refactor: restructure project layout

- Move main process to electron/main/
- Move preload to electron/preload/
- Add shared types in electron/shared/
- Split redis-service into modular redis/ directory
- Flatten renderer to src/ (remove src/renderer/ nesting)
- Update electron.vite.config.ts paths
- Update tsconfig paths
- Output to electron-dist/

.gitignore

@@ -1,6 +1,7 @@
 node_modules/
 out/
 dist/
+electron-dist/
 *.log
 npm-debug.log*
 yarn-debug.log*