Read a store's config from the registry record

`GET /api/stores` records now carry a `config` field — a store's `config.json` moved
into the record that already said what the store is — and the client applies it
directly. Installing a store no longer depends on a second repository existing and
staying reachable, and a store can be configured from the site's admin alone.

The order is registry config, then a repository's `config.json`, then the engine's
defaults. The middle one is why nothing has to move at once: a registry whose stores
have not been migrated is read exactly as before.

The window cannot supply a config. It is handed stores to show and hands one back to
install, but only as an identity: `RegistryStoreDtoMapper.toModel` drops the config and
`StoreProvisioningService` reads the record again from the registry first. A config
decides where files are written and, through `paths.subfolder`, which subtree the store
may later delete from — not a decision the renderer gets to make, for the same reason a
`GameDto` carries no paths. Tested by installing from a record carrying
`subfolder: "ATTACKER"` and `install_root: "/tmp/pwned"` and finding neither on disk.

A store that has left the registry, or a registry that cannot be re-read, still
installs: it falls back to the engine's defaults rather than refusing.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

package.json

@@ -1,7 +1,7 @@
 {
   "name": "warp-engine-client",
   "productName": "WarpEngine Client",
-  "version": "2.0.0",
+  "version": "2.1.0",
   "description": "Graphical client for WarpEngine stores: install a catalog into your own application menu.",
   "license": "MIT",
   "author": "Teletype Games <games@teletype.hu>",