Add support for growable inputs (#6830)

![autogrow-optional_00002](https://github.com/user-attachments/assets/79bfe703-23d7-45fb-86ce-88baa9eaf582)

Also fixes connections to widget inputs created by a dynamic combo
breaking on reload.

Performs some refactoring to group the prior dynamic inputs code.

See also, the overarching frontend PR: comfyanonymous/ComfyUI#10832

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6830-Add-support-for-growable-inputs-2b36d73d365081c484ebc251a10aa6dd)
by [Unito](https://www.unito.io)

src/lib/litegraph/src/LGraphNode.ts

@@ -415,6 +415,7 @@ export class LGraphNode
   selected?: boolean
   showAdvanced?: boolean
 
+  declare comfyMatchType?: Record<string, Record<string, string>>
   declare comfyClass?: string
   declare isVirtualNode?: boolean
   applyToGraph?(extraLinks?: LLink[]): void
@@ -1651,19 +1652,6 @@ export class LGraphNode
     this.onInputRemoved?.(slot, slot_info[0])
     this.setDirtyCanvas(true, true)
   }
-  spliceInputs(
-    startIndex: number,
-    deleteCount = -1,
-    ...toAdd: INodeInputSlot[]
-  ): INodeInputSlot[] {
-    if (deleteCount < 0) return this.inputs.splice(startIndex)
-    const ret = this.inputs.splice(startIndex, deleteCount, ...toAdd)
-    this.inputs.slice(startIndex).forEach((input, index) => {
-      const link = input.link && this.graph?.links?.get(input.link)
-      if (link) link.target_slot = startIndex + index
-    })
-    return ret
-  }
 
   /**
    * computes the minimum size of a node according to its inputs and output slots
@@ -4002,7 +3990,8 @@ export class LGraphNode
         isValidTarget ||
         !slot.isWidgetInputSlot ||
         this.#isMouseOverWidget(this.getWidgetFromSlot(slot)) ||
-        slot.isConnected
+        slot.isConnected ||
+        slot.alwaysVisible
       ) {
         ctx.globalAlpha = isValid ? editorAlpha : 0.4 * editorAlpha
         slot.draw(ctx, {

src/lib/litegraph/src/interfaces.ts

@@ -343,6 +343,7 @@ export interface IWidgetLocator {
 export interface INodeInputSlot extends INodeSlot {
   link: LinkId | null
   widget?: IWidgetLocator
+  alwaysVisible?: boolean
 
   /**
    * Internal use only; API is not finalised and may change at any time.

src/lib/litegraph/src/node/NodeInputSlot.ts

@@ -17,6 +17,7 @@ import type { IBaseWidget } from '@/lib/litegraph/src/types/widgets'
 
 export class NodeInputSlot extends NodeSlot implements INodeInputSlot {
   link: LinkId | null
+  alwaysVisible?: boolean
 
   get isWidgetInputSlot(): boolean {
     return !!this.widget