A registry record is a name and a catalog

`config` — added this morning in 2.1.0 — is gone, and `storeRepositoryUrl` with it, along
with the two store repositories they pointed at.

2.1.0 had the registry say how each store behaves. Wrong shape: how a store behaves is
fixed per installed client, and this application is the only thing that can see the
machine it runs on. A copy of that on a server was a second authority over decisions this
side had already made correctly — including which directories the store may delete from —
and two authorities are a way to disagree.

Keeping two stores on one machine apart needs none of it. It is a subfolder, derived here:
the store id is a slug of the catalog host, the home is `<id>-desktop`, the games folder is
`<id>`, and that folder is the only subtree the store will ever delete from. Derived from
the *catalog* on purpose — the catalog is what a store is, so two records naming the same
one are the same store and land in the same place, which makes installing twice idempotent
instead of a way to orphan what is already there.

Existing installations keep their identity: a store home is recognised by its own
`config.json`, so one installed as `ttg` stays `ttg` in `ttg-desktop` with its games where
they are. Only a new install derives its id.

`StoreProvisioningService` no longer re-reads the registry before installing. That existed
to keep the renderer from supplying a config, and with no config in the record there is
nothing left to protect: a name and a catalog have no paths in them.

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

src/main/ipc/IpcArguments.ts

@@ -27,12 +27,9 @@ export function requireStringArray (value: unknown, name: string): readonly stri
 export function requireRegistryStore (value: unknown): RegistryStoreDto {
   const record = asRecord(value)
   if (record === null) throw new TypeError('a store record is required')
-  const repository = readString(record, 'storeRepositoryUrl')
   const store: RegistryStoreDto = {
     name: readString(record, 'name'),
     catalogUrl: readString(record, 'catalogUrl'),
-    // Optional: a store with no repository installs on the engine's defaults.
-    storeRepositoryUrl: repository.length > 0 ? repository : null,
     storeId: readString(record, 'storeId')
   }
   if (store.name.length === 0 || store.catalogUrl.length === 0) {