Restructure registry installation target into dedicated subfolders

[alamenai]

Description

When users install a component via npx shadcn@latest add https://www.terrae.dev/map.json, all files land flat in a single components/ui/map/ folder — components, types, hooks, and utilities side by side.

Two problems with this:

1. Flat structure — as the library grows, mixing components, hooks, types, and utilities in one folder becomes hard to navigate.
2. Generic folder name — map/ can conflict with other libraries. We should use the brand name terrae/ instead.
3. Wrong location for non-components — hooks, types, and utilities are not UI components and shouldn't live inside components/ui/.

Current structure

components/ui/map/
├── map.tsx
├── compass.tsx
├── marker.tsx
├── popup.tsx
├── types.ts
├── hooks.ts
├── map-library.ts
└── ...

Proposed structure

components/ui/terrae/
├── map.tsx
├── compass.tsx
├── marker.tsx
└── popup.tsx

hooks/terrae/
└── use-map.ts

lib/terrae/
└── map-library.ts

types/terrae/
└── types.ts

This follows the standard Next.js/shadcn convention:

• components/ui/terrae/ — only actual React components
• hooks/terrae/ — aligns with where shadcn projects already put hooks
• lib/terrae/ — aligns with the existing lib/utils.ts pattern
• types/terrae/ — pure type definitions

Each folder is namespaced under terrae/ to avoid conflicts with other libraries.

Impact

This requires updating the target field in every registry JSON file under public/. For example in map.json:

- "target": "components/ui/map/map.tsx"
+ "target": "components/ui/terrae/map.tsx"

- "target": "components/ui/map/types.ts"
+ "target": "types/terrae/types.ts"

- "target": "components/ui/map/hooks.ts"
+ "target": "hooks/terrae/use-map.ts"

- "target": "components/ui/map/map-library.ts"
+ "target": "lib/terrae/map-library.ts"

All internal imports within components also need to be updated to reflect the new paths.

Affected Component

All components — this is a cross-cutting structural change to the registry.