fix: add explicit type annotations to extension callback parameters (#8966)

Fixes #8882

Adds explicit type annotations to all extension callback parameters
(`nodeCreated`, `beforeRegisterNodeDef`, `addCustomNodeDefs`) across 14
core extension files. While the types were already inferred from the
`ComfyExtension` interface, explicit annotations improve readability and
make the code self-documenting.

## Changes

- Annotate `node` parameter as `LGraphNode` in all `nodeCreated`
callbacks
- Annotate `nodeType` as `typeof LGraphNode` and `nodeData` as
`ComfyNodeDef` in all `beforeRegisterNodeDef` callbacks
- Annotate `defs` as `Record<string, ComfyNodeDef>` in
`addCustomNodeDefs`
- Add necessary type imports where missing

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8966-fix-add-explicit-type-annotations-to-extension-callback-parameters-30b6d73d36508125b074f509aa38145f)
by [Unito](https://www.unito.io)

src/extensions/core/uploadAudio.ts

@@ -88,7 +88,10 @@ async function uploadFile(
 // present.
 app.registerExtension({
   name: 'Comfy.AudioWidget',
-  async beforeRegisterNodeDef(nodeType, nodeData) {
+  async beforeRegisterNodeDef(
+    nodeType: typeof LGraphNode,
+    nodeData: ComfyNodeDef
+  ) {
     if (
       [
         'LoadAudio',
@@ -179,7 +182,10 @@ app.registerExtension({
 
 app.registerExtension({
   name: 'Comfy.UploadAudio',
-  async beforeRegisterNodeDef(_nodeType, nodeData: ComfyNodeDef) {
+  async beforeRegisterNodeDef(
+    _nodeType: typeof LGraphNode,
+    nodeData: ComfyNodeDef
+  ) {
     if (nodeData?.input?.required?.audio?.[1]?.audio_upload === true) {
       nodeData.input.required.upload = ['AUDIOUPLOAD', {}]
     }
@@ -419,7 +425,7 @@ app.registerExtension({
     }
   },
 
-  async nodeCreated(node) {
+  async nodeCreated(node: LGraphNode) {
     if (node.constructor.comfyClass !== 'RecordAudio') return
 
     await useAudioService().registerWavEncoder()