Type src/ against API and database shapes, fixing implicit anys

Adds .d.ts declarations beside the untyped JS modules imported from
TS (api.js, navConfig.js, adminSchema.js, adminNav.js, src/data/*),
with shapes taken from the server routes and migrations. get/post/
patch/del now return unknown unless the caller names the response.

Fixes found along the way:
- website/email/instagram are bare strings from splitLinks, not Link
  objects; OrganizationDetail's website and email pills rendered with
  no href or label and now link correctly.
- The chapter map falls back to FALLBACK_COLOR for a region with no
  colour instead of painting its tiles black.

Adds defineSection() so each page manifest entry's props are checked
against its own Component.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/components/PageShell.tsx

@@ -29,9 +29,27 @@
      />
    ═══════════════════════════════════════════════════════════════ */
 
+import type { ReactNode } from "react";
+
 const TEAL = "#138ba0";
 
-export function Section({ section }) {
+export type ShellSection = {
+  id: string;
+  title: string;
+  blurb?: string;
+  accent: string;
+  background: string;
+  actions?: ReactNode;
+  content: ReactNode;
+};
+
+type PageShellProps = {
+  title: ReactNode;
+  intro?: ReactNode;
+  sections: ShellSection[];
+};
+
+export function Section({ section }: { section: ShellSection }) {
   const {
     id,
     title,
@@ -70,7 +88,7 @@ export function Section({ section }) {
   );
 }
 
-export default function PageShell({ title, intro, sections }) {
+export default function PageShell({ title, intro, sections }: PageShellProps) {
   return (
     <>
       {/* Page header */}