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/lib/adminTitle.tsx

@@ -14,12 +14,14 @@
 
 import { createContext, useContext, useEffect } from "react";
 
-export const AdminTitleContext = createContext(null);
+export type AdminTitleValue = { setDetail: (value: string | null) => void };
+
+export const AdminTitleContext = createContext<AdminTitleValue | null>(null);
 
 /* Publish the name of whatever this page is showing. Clears on
    unmount, so navigating away can't leave a stale record name in
    the tab. */
-export function useAdminDetail(name) {
+export function useAdminDetail(name: string | null | undefined) {
   const setDetail = useContext(AdminTitleContext)?.setDetail;
 
   useEffect(() => {