feat: initialize thoughts-frontend with Next.js, TypeScript, and ESLint

- Add ESLint configuration for Next.js and TypeScript support.
- Create Next.js configuration file with standalone output option.
- Initialize package.json with scripts for development, build, and linting.
- Set up PostCSS configuration for Tailwind CSS.
- Add SVG assets for UI components.
- Create TypeScript configuration for strict type checking and module resolution.

thoughts-backend/models/README.md

@@ -0,0 +1,13 @@
+# models
+
+No axum or api dependencies should be introduced into this folder.
+Only dependencies for modelling are allowed:
+
+- serde (JSON serialization/deserialization)
+- SeaORM (domain models and database)
+- validator (parameter validation)
+- utoipa (openapi)
+
+## SeaORM
+
+Write migration files first, then generate models.