refactor: consolidate NodeId type aliases (pre-work for adr008)

Issue #11428 identified three competing `NodeId` definitions:
  - src/lib/litegraph/src/LGraphNode.ts        (number | string)
  - src/platform/workflow/validation/schemas/workflowSchema.ts (number | string)
  - src/renderer/core/layout/types.ts          (string)

Make `LGraphNode.NodeId` the canonical source. `workflowSchema.ts`
now re-exports it (same shape, single definition) and `zNodeId` gets
a `satisfies z.ZodType<NodeId>` guard so the validator and the type
can never drift. The renderer's narrower `string`-only alias is kept
as an intentional layered variant and documented as such.

No behavior change. Existing import sites continue to work via the
re-export. Sweep of the ~151 bare-string `nodeId` typings will land
in follow-up PRs scoped by domain (litegraph internals, renderer,
stores, Vue props).

Refs #11428

src/lib/litegraph/src/LGraphNode.ts

@@ -98,6 +98,21 @@ import type { WidgetTypeMap } from './widgets/widgetMap'
 
 // #region Types
 
+/**
+ * Canonical identifier type for a litegraph node.
+ *
+ * This is the single source of truth for node IDs across the litegraph
+ * library and the workflow schema layer. Other modules SHOULD import
+ * `NodeId` from here (or via the workflow schema re-export) rather than
+ * declaring local `string` / `number | string` aliases.
+ *
+ * Note: `src/renderer/core/layout/types.ts` deliberately defines a
+ * narrower `NodeId = string` for the Vue-node renderer, where IDs are
+ * normalized to strings. That is a separate, intentionally-narrower
+ * layered alias — see the JSDoc there.
+ *
+ * Tracking issue for full migration: #11428.
+ */
 export type NodeId = number | string
 
 export type NodeProperty = string | number | boolean | object

src/platform/workflow/validation/schemas/workflowSchema.ts

@@ -1,7 +1,9 @@
 import { z } from 'zod'
 import type { SafeParseReturnType } from 'zod'
 import { fromZodError } from 'zod-validation-error'
+
 import type { RendererType } from '@/lib/litegraph/src/LGraph'
+import type { NodeId } from '@/lib/litegraph/src/LGraphNode'
 
 const zRendererType = z.enum([
   'LG',
@@ -12,9 +14,20 @@ const zRendererType = z.enum([
 // GroupNode is hacking node id to be a string, so we need to allow that.
 // innerNode.id = `${this.node.id}:${i}`
 // Remove it after GroupNode is redesigned.
-export const zNodeId = z.union([z.number().int(), z.string()])
+export const zNodeId = z.union([
+  z.number().int(),
+  z.string()
+]) satisfies z.ZodType<NodeId>
 const zNodeInputName = z.string()
-export type NodeId = z.infer<typeof zNodeId>
+
+/**
+ * Re-export of the canonical {@link NodeId} type defined in
+ * `src/lib/litegraph/src/LGraphNode.ts`. Kept here for ergonomic imports
+ * alongside `zNodeId` (the runtime validator) and historical call sites.
+ *
+ * See issue #11428 for the consolidation rationale.
+ */
+export type { NodeId }
 
 /**
  * UUID identifier for a saved workflow.

src/renderer/core/layout/types.ts

@@ -37,6 +37,20 @@ export interface NodeBoundsUpdate {
   bounds: Bounds
 }
 
+/**
+ * Renderer-internal node identifier.
+ *
+ * Intentionally narrower than the canonical {@link NodeId} in
+ * `src/lib/litegraph/src/LGraphNode.ts` (which is `number | string`).
+ * The Vue-node renderer normalizes all incoming IDs to strings before
+ * they enter the layout system, so this layered alias documents and
+ * enforces that contract at the renderer boundary.
+ *
+ * If you need a node ID at the litegraph or workflow-schema layer,
+ * import `NodeId` from `@/lib/litegraph/src/LGraphNode` instead.
+ *
+ * See issue #11428 for the layered-types decision.
+ */
 export type NodeId = string
 export type LinkId = number
 export type RerouteId = number