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/useRecord.ts

@@ -89,7 +89,7 @@ export function useRecord<T>(path: string | null, key: string): Resource<T> {
       setError(null)
       setNotFound(false)
       try {
-        const body = await get(path as string)
+        const body = await get<Record<string, unknown> | null>(path as string)
         if (!live) return
         // A 200 with the key absent is a server-side shaping bug,
         // not an empty record. Say so rather than rendering a page