fix(cloudflare/workers-for-platforms): type getDispatchNamespaceScriptSetting errors + loosen placement

[sam-goodwin]

Make the Workers for Platforms script-settings endpoint usable from typed consumers.

getDispatchNamespaceScriptSetting:

• Type its error union (it previously carried only the generic HTTP catch-alls):

{ "errors": {
  "DispatchNamespaceNotFound": [{ "code": 100119 }],
  "DispatchNamespaceScriptNotFound": [{ "code": 10007 }],
  "Forbidden": [{ "status": 403 }]
} }

• Fix placement decoding. The vendor SDK models the response placement with the request union — every variant requires mode/region/hostname/host — so the real response ({} when unset, or { mode, status, last_analyzed_at }) matches no variant and fails to decode. The vendor SDK only gets away with it because it never validates the response at runtime.

  We keep the upstream union verbatim and append the one variant it omits for the response — the all-optional placement-status object:

  placement?:
    | { mode: "smart" }
    | { region: string }
    | /* …upstream's targeted / hostname / host variants… */
    | {                                  // appended
        mode?: "smart" | null;
        status?: "SUCCESS" | "UNSUPPORTED_APPLICATION" | "INSUFFICIENT_INVOCATIONS" | (string & {}) | null;
        lastAnalyzedAt?: string | null;  // wire: last_analyzed_at
      }
    | null;

  Uses the existing appendUnion patch op — no parser/model/codegen change. (This is a semantic gap in the vendor spec, not a representation gap on our side; the generator already reproduces upstream's union faithfully — which is exactly why it failed.)

Found while wiring the alchemy Cloudflare Worker resource to deploy into a dispatch namespace: the post-upload settings read needed both the typed not-found tags and a response that actually decodes.

🤖 Generated with Claude Code

[alchemy-version-bot]

Install the packages built from this commit:

@distilled.cloud/core

bun add @distilled.cloud/core@https://pkg.distilled.cloud/core/e824e87

@distilled.cloud/aws

bun add @distilled.cloud/aws@https://pkg.distilled.cloud/aws/e824e87

@distilled.cloud/cloudflare

bun add @distilled.cloud/cloudflare@https://pkg.distilled.cloud/cloudflare/e824e87