feat(cloudflare): exportAs patch directive to hoist named union type aliases

[sam-goodwin]

Adds an exportAs property-patch directive that hoists a well-known inline union into an exported named type alias, and applies it to the Workers script-upload binding union (previously repeated anonymously inline in ~8 request/response structs).

// patches/workers/putScript.json
"metadata.bindings[]": { "exportAs": "Binding" }

generates

export interface WorkersBindingKindD1 { ... }
export interface WorkersBindingKindDurableObjectNamespace2 { ... }
// ...one exported interface per variant
export type Binding = WorkersBindingKindAI | WorkersBindingKindD1 | ... | WorkerLoaderBinding | ArtifactsBinding | RatelimitBinding;

export interface PutScriptRequest {
  metadata: { bindings?: Binding[]; ... };
}

so consumers write workers.Binding instead of Exclude<workers.PutScriptRequest["metadata"]["bindings"], undefined>[number].

• Variant naming is source-first: a structurally identical module-private def whose name came from the upstream SDK (WorkersBindingKindD1) is promoted to export interface rather than duplicated under a new name; suffixes (WorkersBindingKindDurableObjectNamespace2) now appear only where request and response shapes genuinely differ. Patch-appended variants without an upstream name get discriminant-derived names (WorkerLoaderBinding, ArtifactsBinding, RatelimitBinding).
• The TS-type emitter still inlines module-private refs (public types stay self-contained); only exported refs render by name. The schema emitter's ref short-circuit is generalized so the union's schema const resolves by name too.
• Misuse fails generation loudly: one exportAs name targeting two structurally different unions, or a name colliding with an existing top-level identifier, throws.
• Directives applied: putScript request metadata.bindings[] → Binding, getScriptScriptAndVersionSetting response bindings[] → SettingsBinding. Only the workers service was regenerated (−590 lines from collapsing the repeated inline unions).

Verified with bun tsc -b from the alchemy workspace root and live WorkerEnv / WorkerBinding test suites (deploying real Workers through the regenerated putScript/settings schemas).

🤖 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/0d915a3

@distilled.cloud/cloudflare

bun add @distilled.cloud/cloudflare@https://pkg.distilled.cloud/cloudflare/0d915a3

@distilled.cloud/planetscale

bun add @distilled.cloud/planetscale@https://pkg.distilled.cloud/planetscale/0d915a3