Implement fullstack education catalog with disease detail pages, API routes, and shared types

- Add disease detail page component with data fetching and error handling
- Create shared types for diseases and classifications
- Implement API routes for diseases, classifications, and dashboard summary
- Develop reusable components for risk badge and disease card
- Build catalog page with search and filter functionality
- Update dashboard page with data-backed summary and manual classification form
- Register new routes in the web application
- Ensure type safety and consistency across shared modules

packages/shared/src/classifications.ts

@@ -0,0 +1,23 @@
+import type { DiseaseCatalogItem, DiseaseSlug, RiskLevel } from './diseases';
+
+export type ManualClassificationRequest = {
+  diseaseSlug: DiseaseSlug;
+  observation: string;
+  location: string;
+};
+
+export type ManualClassificationRecord = {
+  id: string;
+  diseaseSlug: DiseaseSlug;
+  observation: string;
+  location: string;
+  createdAt: string;
+  disease: DiseaseCatalogItem;
+};
+
+export type DashboardSummary = {
+  diseaseCount: number;
+  classificationCount: number;
+  latestClassification: ManualClassificationRecord | null;
+  riskDistribution: Record<RiskLevel, number>;
+};