feat: add Einnahmen Kategorien management page with CRUD functionality

- Implemented a new route for managing Einnahmen Kategorien.
- Added auto-seeding of default Einnahmen Kategorien if none exist.
- Integrated category usage tracking to prevent deletion of in-use categories.
- Enhanced Einnahmen page to link to the new Kategorien management.
- Updated Prisma schema and seed script to include default categories.
- Added a modal for detailed view of Einnahmen by category and month.
- Refactored existing Einnahmen page to accommodate new category structure.
- Introduced PostCSS configuration for Tailwind CSS support.
- Created a new migration to update existing category labels in the database.
- Added TypeScript configuration for stricter type checking.
- Set up Vite configuration for improved development experience with React Router.

app/routes.ts

@@ -19,7 +19,9 @@ export default [
     route("companies/:id/reports", "routes/companies.$id.reports.tsx"),
     route("companies/:id/bilanzen", "routes/companies.$id.bilanzen.tsx"),
     route("companies/:id/ausgaben", "routes/companies.$id.ausgaben.tsx"),
+    route("companies/:id/ausgaben/kategorien", "routes/companies.$id.ausgaben.kategorien.tsx"),
     route("companies/:id/einnahmen", "routes/companies.$id.einnahmen.tsx"),
+    route("companies/:id/einnahmen/kategorien", "routes/companies.$id.einnahmen.kategorien.tsx"),
     route("companies/:id/anlagevermoegen", "routes/companies.$id.anlagevermoegen.tsx"),
     route("companies/:id/money", "routes/companies.$id.money.tsx"),
     route("archiv", "routes/archiv.tsx"),
@@ -55,6 +57,8 @@ export default [
   route("api/ausgaben/:id", "routes/api.ausgaben.$id.ts"),
   route("api/einnahmen", "routes/api.einnahmen.ts"),
   route("api/einnahmen/:id", "routes/api.einnahmen.$id.ts"),
+  route("api/companies/:id/buchungkategorien", "routes/api.companies.$id.buchungkategorien.ts"),
+  route("api/companies/:id/buchungkategorien/:katId", "routes/api.companies.$id.buchungkategorien.$katId.ts"),
   route("api/anlagevermoegen", "routes/api.anlagevermoegen.ts"),
   route("api/anlagevermoegen/:id", "routes/api.anlagevermoegen.$id.ts"),