refactor(cloudflare): use named workers.Binding/SettingsBinding from distilled

[sam-goodwin]

distilled now exports the Workers script-upload binding union as named type aliases (alchemy-run/distilled#381), so the Exclude<...>[number] digs go away:

-export type WorkerBinding = Exclude<
-  workers.PutScriptRequest["metadata"]["bindings"],
-  undefined
->[number];
+export type WorkerBinding = workers.Binding;

-export type WorkerSettingsBinding = Exclude<
-  workers.GetScriptScriptAndVersionSettingResponse["bindings"],
-  null | undefined
->[number];
+export type WorkerSettingsBinding = workers.SettingsBinding;

• Bumps the distilled submodule to pick up the named aliases (and one exported interface per variant, e.g. workers.WorkersBindingKindDurableObjectNamespace2).
• Optional variant props are now honestly nullable (matching what the runtime schema accepts/decodes), so toRuntimeBinding in LocalWorkerProvider coalesces null to undefined where local-mode helpers expect string | undefined.

Verified with bun tsc -b and live WorkerEnv / WorkerBinding suites against real Cloudflare.

🤖 Generated with Claude Code