fix: remove duplicate assertSelectableAdapterType that shadowed async version

The sync version from upstream was duplicated alongside the fork's async
version that includes the paperclip_runner rollout flag check. The sync
version shadowed the async one, disabling the flag validation.

Author: claude

server/src/routes/agents.ts

@@ -1607,30 +1607,6 @@ export function agentRoutes(
    * A disabled adapter is one this instance cannot run — most often because a
    * declarative registry (PAPERCLIP_ADAPTERS) curated it out, which
    * reconcileAdapterAvailability turns into a disabled type at boot. Registered
-   * but disabled still passes assertKnownAdapterType, so an agent could be
-   * created on it and then fail EVERY run at lease time with
-   * `Adapter "..." is not in the configured adapter registry` — an error that
-   * arrives minutes later, in a run log, with no way back to the choice that
-   * caused it. Refuse at selection time instead, and name what can be chosen.
-   *
-   * Existing agents on a now-disabled adapter are deliberately untouched
-   * (listEnabledServerAdapters documents the same rule: hidden from selection,
-   * still functional for agents that already use them).
-   */
-  function assertSelectableAdapterType(type: string | null | undefined): string {
-    const adapterType = assertKnownAdapterType(type);
-    const disabled = new Set(getDisabledAdapterTypes());
-    if (!disabled.has(adapterType)) return adapterType;
-    const available = listServerAdapters()
-      .map((a) => a.type)
-      .filter((t) => !disabled.has(t))
-      .sort();
-    throw unprocessable(
-      `Adapter "${adapterType}" is not available on this instance. `
-      + `Available adapters: ${available.length > 0 ? available.join(", ") : "(none configured)"}`,
-    );
-  }
-
   async function assertAgentDefaultEnvironmentSelection(
     companyId: string,
     environmentId: string | null | undefined,