feat: implement incident reporting and management system

- Add incident reporting routes and logic to handle creation, updating, and retrieval of incidents.
- Implement visibility rules for users based on roles (reporters, supervisors).
- Create tests for incident reporting functionality to ensure correctness and reliability.
- Introduce site and area management routes, including validation for area hierarchy.
- Establish user management routes with role-based access control for creating and updating users.
- Add setup routes for initializing the application with an organization and admin user.
- Implement shared enums and schemas for consistent validation and data handling across the application.
- Create a test helper for setting up an in-memory database and API client for testing.
- Add TypeScript configuration for server-side code with strict type checking and module resolution.

server/lib/audit.ts

@@ -0,0 +1,29 @@
+import type { Db } from '../db/client.ts'
+import { auditLog } from '../db/schema.ts'
+
+interface AuditEntry {
+  organizationId: string
+  actorId: string | null
+  entityType: string
+  entityId: string
+  action: string
+  changes?: Record<string, unknown> | null
+}
+
+export async function audit(db: Db, entry: AuditEntry): Promise<void> {
+  await db.insert(auditLog).values({ ...entry, changes: entry.changes ?? null })
+}
+
+const comparable = (value: unknown) => (value instanceof Date ? value.toISOString() : (value ?? null))
+
+/** `{ field: [before, after] }` for each field in `next` whose value differs from `current`. */
+export function diff(current: Record<string, unknown>, next: Record<string, unknown>): Record<string, [unknown, unknown]> {
+  const changes: Record<string, [unknown, unknown]> = {}
+  for (const [key, value] of Object.entries(next)) {
+    if (value === undefined) continue
+    const before = comparable(current[key])
+    const after = comparable(value)
+    if (JSON.stringify(before) !== JSON.stringify(after)) changes[key] = [before, after]
+  }
+  return changes
+}