feat: initialize project structure with core components and pages

- Added shared styles for UI components in `src/components/styles.ts`.
- Created configuration constants in `src/lib/config.ts`.
- Implemented date formatting and greeting functions in `src/lib/dates.ts` and corresponding tests in `src/lib/dates.test.ts`.
- Developed incident management functions in `src/lib/incidents.ts` with tests in `src/lib/incidents.test.ts`.
- Established navigation structure in `src/lib/navigation.ts`.
- Seeded demo data for incidents and users in `src/lib/seed.ts`.
- Defined tone classes for UI elements in `src/lib/tones.ts`.
- Created type definitions for incidents and related entities in `src/lib/types.ts`.
- Set up main application entry point in `src/main.tsx`.
- Developed various pages including About, Analytics, Incidents, Locations, Overview, and Report Incident.
- Configured testing setup in `src/test/setup.ts` and TypeScript configurations.
- Integrated Vite for development and testing with appropriate plugins.

src/components/PageIntro.tsx

@@ -0,0 +1,22 @@
+import type { ReactNode } from 'react'
+import { Eyebrow } from './Eyebrow'
+
+interface PageIntroProps {
+  eyebrow: string
+  title: string
+  copy?: string
+  action?: ReactNode
+}
+
+export function PageIntro({ eyebrow, title, copy, action }: PageIntroProps) {
+  return (
+    <div className="mb-[31px] flex flex-col items-start gap-5 sm:flex-row sm:items-center sm:justify-between">
+      <div>
+        <Eyebrow>{eyebrow}</Eyebrow>
+        <h1 className="mt-[7px] mb-[5px] font-display text-[29px] font-semibold tracking-[-1px] text-ink sm:text-[34px]">{title}</h1>
+        {copy && <p className="text-sm text-muted">{copy}</p>}
+      </div>
+      {action}
+    </div>
+  )
+}