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>

src/infrastructure/repositories/HttpStoreRegistryRepository.ts

@@ -1,7 +1,7 @@
 import { RegistryUnavailableError } from '../../domain/errors/RegistryUnavailableError'
 import type { RegistryStore } from '../../domain/models/RegistryStore'
 import type { StoreRegistryRepository } from '../../domain/ports/StoreRegistryRepository'
-import { asRecord, readString, type JsonRecord } from '../json/JsonRecord'
+import { asRecord, readRecord, readString, type JsonRecord } from '../json/JsonRecord'
 import { BuildConfiguration } from '../config/BuildConfiguration'
 import type { HttpTextClient } from '../http/HttpTextClient'
 
@@ -15,10 +15,10 @@ const DEFAULT_REGISTRY_URL = 'https://teletypegames.org/api/stores'
  * field a build was packaged with (for shipping a client for another site), and finally
  * the address of ours.
  *
- * A record needs a name and a catalog URL; those two make a store. The repository
- * is optional and arrives as null when absent — a store configured by nothing but
- * this record installs on the engine's defaults. Records missing either of the two
- * required fields are dropped rather than half-used.
+ * A record needs a name and a catalog URL; those two make a store. The config and the
+ * repository are both optional and arrive as null when absent — a store configured by
+ * nothing but this record installs on the engine's defaults. Records missing either of
+ * the two required fields are dropped rather than half-used.
  */
 export class HttpStoreRegistryRepository implements StoreRegistryRepository {
   public readonly sourceUrl: string
@@ -53,7 +53,8 @@ export class HttpStoreRegistryRepository implements StoreRegistryRepository {
         return {
           name: readString(row, 'name').trim(),
           catalogUrl: (readString(row, 'catalogUrl') || readString(row, 'catalog_url')).trim(),
-          storeRepositoryUrl: repository.length > 0 ? repository : null
+          storeRepositoryUrl: repository.length > 0 ? repository : null,
+          config: readRecord(row, 'config')
         }
       })
       .filter((store: RegistryStore): boolean =>

src/infrastructure/repositories/NativeStoreEngineInstaller.ts

@@ -77,13 +77,15 @@ export class NativeStoreEngineInstaller implements StoreEngineInstaller {
   /**
    * The store's configuration.
    *
-   * Three cases, and all of them install:
+   * Four cases, and all of them install:
    *
-   *   - **a repository with a config.json** — that file is the authority on how the
-   *     store behaves: which platforms it offers, which statuses it shows, where
-   *     things land;
+   *   - **a config on the registry record** — the authority on how the store behaves:
+   *     which platforms it offers, which statuses it shows, where things land. No
+   *     request at all, because it arrived with the store list;
+   *   - **a repository with a config.json** — the same thing in its older home, read
+   *     for a registry whose stores have not moved over yet;
    *   - **a repository without one** (404) — the engine's defaults, as below;
-   *   - **no repository at all** — the same defaults, without the round trip.
+   *   - **neither** — the same defaults, without the round trip.
    *
    * The engine's built-in defaults already cover the host-to-asset mapping, the
    * modes, the platforms and the behaviour, so what a store actually has to supply is
@@ -113,6 +115,13 @@ export class NativeStoreEngineInstaller implements StoreEngineInstaller {
     storeId: string,
     progress: EngineProgressListener
   ): Promise<Record<string, unknown>> {
+    // The registry's own answer wins, and needs no request: a store's configuration is
+    // part of its record now rather than a file in a repository that has to exist and
+    // stay reachable.
+    if (store.config !== null) {
+      progress.onLog?.(`${store.name} is configured by the registry`)
+      return { ...store.config }
+    }
     const repositoryUrl = store.storeRepositoryUrl
     if (repositoryUrl === null) {
       progress.onLog?.(`${store.name} has no store repository — using the engine defaults`)