fix: log RPC errors instead of silently swallowing them

Root cause of empty agents: public Base RPC (mainnet.base.org) was
rate-limiting the worker. Switched BASE_RPC secret to publicnode.com.
Added console.error logging so future RPC failures are visible.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: daimon111

worker/src/index.ts

@@ -341,7 +341,9 @@ async function buildNetworkData(env: Env): Promise<NetworkResponse> {
   let registryAgents: Awaited<ReturnType<typeof fetchRegistryAgents>>;
   try {
     registryAgents = await fetchRegistryAgents(env);
-  } catch {
+  } catch (err) {
+    const msg = err instanceof Error ? err.message : String(err);
+    console.error("fetchRegistryAgents failed:", msg);
     return { agents: [], cachedAt: Date.now() };
   }