docs(litegraph): mark subgraph building blocks as @internal

Per AUDIT-LG.9 §subgraph correction, these subgraph cluster exports
are internal building blocks with no production importers — they leak
into the published @comfyorg/extension-api ABI but should not be part
of the public surface:

- EmptySubgraphInput, EmptySubgraphOutput
- SubgraphSlot (SubgraphSlotBase.ts), SubgraphIONodeBase
- PromotedWidgetViewManager
- subgraphDeduplication (deduplicateSubgraphNodeIds, topologicalSortSubgraphs)
- subgraphUtils (splitPositionables, getBoundaryLinks, multiClone,
  groupResolvedByOutput, mapSubgraphInputsAndLinks,
  mapSubgraphOutputsAndLinks, getDirectSubgraphIds, findUsedSubgraphIds,
  isSubgraphInput, isSubgraphOutput, isNodeSlot)
- SubgraphOutput

Add @internal JSDoc tags so TypeDoc (with excludeInternal: true)
strips them from the published ABI. Preserves SubgraphNode, Subgraph,
SubgraphInput, ExecutableNodeDTO, and subgraphTest/createTestSubgraph
test fixtures — those are external-facing.

src/lib/litegraph/src/subgraph/EmptySubgraphInput.ts

@@ -10,6 +10,8 @@ import type { SubgraphInputNode } from './SubgraphInputNode'
 
 /**
  * A virtual slot that simply creates a new input slot when connected to.
+ *
+ * @internal
  */
 export class EmptySubgraphInput extends SubgraphInput {
   declare parent: SubgraphInputNode

src/lib/litegraph/src/subgraph/EmptySubgraphOutput.ts

@@ -10,6 +10,8 @@ import type { SubgraphOutputNode } from './SubgraphOutputNode'
 
 /**
  * A virtual slot that simply creates a new output slot when connected to.
+ *
+ * @internal
  */
 export class EmptySubgraphOutput extends SubgraphOutput {
   declare parent: SubgraphOutputNode

src/lib/litegraph/src/subgraph/PromotedWidgetViewManager.ts

@@ -9,6 +9,8 @@ type ViewManagerEntry = PromotedWidgetSource & {
  *
  * Keeps object identity stable by key while preserving the current
  * promotion order and deduplicating duplicate entries by first occurrence.
+ *
+ * @internal
  */
 export class PromotedWidgetViewManager<TView> {
   private viewCache = new Map<string, TView>()

src/lib/litegraph/src/subgraph/SubgraphIONodeBase.ts

@@ -29,6 +29,7 @@ import type { Subgraph } from './Subgraph'
 import type { SubgraphInput } from './SubgraphInput'
 import type { SubgraphOutput } from './SubgraphOutput'
 
+/** @internal */
 export abstract class SubgraphIONodeBase<
   TSlot extends SubgraphInput | SubgraphOutput
 >

src/lib/litegraph/src/subgraph/SubgraphOutput.ts

@@ -27,6 +27,8 @@ import { isNodeSlot, isSubgraphInput } from './subgraphUtils'
  * You have "Subgraph Outputs", because they go from inside the subgraph and out, but links to them come from "node outputs".
  *
  * Functionally, however, when editing a subgraph, that "subgraph output" is the "target" or "input side" of a link.
+ *
+ * @internal
  */
 export class SubgraphOutput extends SubgraphSlot {
   declare parent: SubgraphOutputNode

src/lib/litegraph/src/subgraph/SubgraphSlotBase.ts

@@ -37,7 +37,11 @@ interface SubgraphSlotDrawOptions {
   editorAlpha?: number
 }
 
-/** Shared base class for the slots used on Subgraph . */
+/**
+ * Shared base class for the slots used on Subgraph .
+ *
+ * @internal
+ */
 export abstract class SubgraphSlot
   extends SlotBase
   implements SubgraphIO, Hoverable, Serialisable<SubgraphIO>

src/lib/litegraph/src/subgraph/subgraphDeduplication.ts

@@ -28,6 +28,8 @@ interface DeduplicationResult {
  * @param reservedNodeIds - Node IDs already in use by root-level nodes
  * @param state - Graph state containing the `lastNodeId` counter (mutated)
  * @param rootNodes - Optional root-level nodes with proxyWidgets to patch
+ *
+ * @internal
  */
 export function deduplicateSubgraphNodeIds(
   subgraphs: ExportedSubgraph[],
@@ -148,6 +150,8 @@ function patchPromotedWidgets(
  *
  * Falls back to the original order if no reordering is needed or if the
  * dependency graph contains cycles.
+ *
+ * @internal
  */
 export function topologicalSortSubgraphs(
   subgraphs: ExportedSubgraph[]

src/lib/litegraph/src/subgraph/subgraphUtils.ts

@@ -37,6 +37,7 @@ interface FilteredItems {
   unknown: Set<Positionable>
 }
 
+/** @internal */
 export function splitPositionables(
   items: Iterable<Positionable>
 ): FilteredItems {
@@ -89,6 +90,7 @@ interface BoundaryLinks {
   boundaryOutputLinks: LLink[]
 }
 
+/** @internal */
 export function getBoundaryLinks(
   graph: LGraph,
   items: Set<Positionable>
@@ -213,6 +215,7 @@ export function getBoundaryLinks(
   }
 }
 
+/** @internal */
 export function multiClone(nodes: Iterable<LGraphNode>): ISerialisedNode[] {
   const clonedNodes: ISerialisedNode[] = []
 
@@ -240,6 +243,8 @@ export function multiClone(nodes: Iterable<LGraphNode>): ISerialisedNode[] {
  * Groups resolved connections by output object. If the output is nullish, the connection will be in its own group.
  * @param resolvedConnections The resolved connections to group
  * @returns A map of grouped connections.
+ *
+ * @internal
  */
 export function groupResolvedByOutput(
   resolvedConnections: ResolvedConnection[]
@@ -278,6 +283,7 @@ function mapReroutes(
   return lastId
 }
 
+/** @internal */
 export function mapSubgraphInputsAndLinks(
   resolvedInputLinks: ResolvedConnection[],
   links: SerialisableLLink[],
@@ -358,6 +364,8 @@ export function mapSubgraphInputsAndLinks(
  * @param resolvedOutputLinks The resolved output links.
  * @param links The links to add to the subgraph.
  * @returns The subgraph output slots.
+ *
+ * @internal
  */
 export function mapSubgraphOutputsAndLinks(
   resolvedOutputLinks: ResolvedConnection[],
@@ -436,6 +444,8 @@ export function mapSubgraphOutputsAndLinks(
  * Collects all subgraph IDs used directly in a single graph (non-recursive).
  * @param graph The graph to check for subgraph nodes
  * @returns Set of subgraph IDs used in this graph
+ *
+ * @internal
  */
 export function getDirectSubgraphIds(graph: GraphOrSubgraph): Set<SubgraphId> {
   const subgraphIds = new Set<SubgraphId>()
@@ -454,6 +464,8 @@ export function getDirectSubgraphIds(graph: GraphOrSubgraph): Set<SubgraphId> {
  * @param rootGraph The graph to start from
  * @param subgraphRegistry Map of all available subgraphs
  * @returns Set of all subgraph IDs found
+ *
+ * @internal
  */
 export function findUsedSubgraphIds(
   rootGraph: GraphOrSubgraph,
@@ -484,6 +496,8 @@ export function findUsedSubgraphIds(
  * Type guard to check if a slot is a SubgraphInput.
  * @param slot The slot to check
  * @returns true if the slot is a SubgraphInput
+ *
+ * @internal
  */
 export function isSubgraphInput(slot: unknown): slot is SubgraphInput {
   return (
@@ -498,6 +512,8 @@ export function isSubgraphInput(slot: unknown): slot is SubgraphInput {
  * Type guard to check if a slot is a SubgraphOutput.
  * @param slot The slot to check
  * @returns true if the slot is a SubgraphOutput
+ *
+ * @internal
  */
 export function isSubgraphOutput(slot: unknown): slot is SubgraphOutput {
   return (
@@ -512,6 +528,8 @@ export function isSubgraphOutput(slot: unknown): slot is SubgraphOutput {
  * Type guard to check if a slot is a regular node slot (INodeInputSlot or INodeOutputSlot).
  * @param slot The slot to check
  * @returns true if the slot is a regular node slot
+ *
+ * @internal
  */
 export function isNodeSlot(
   slot: unknown