feat: add custom words autocomplete support for Prompt node

Adds custom words autocomplete functionality similar to comfyui-custom-scripts,
with the following features:

Backend (Python):
- Create CustomWordsService for CSV parsing and priority-based search
- Add API endpoints: GET/POST /api/lm/custom-words and
  GET /api/lm/custom-words/search
- Share storage with pysssss plugin (checks for their user/autocomplete.txt first)
- Fallback to Lora Manager's user directory for storage

Frontend (JavaScript/Vue):
- Add 'custom_words' and 'prompt' model types to autocomplete system
- Prompt node now supports dual-mode autocomplete:
  * Type 'emb:' prefix → search embeddings
  * Type normally → search custom words (no prefix required)
- Add AUTOCOMPLETE_TEXT_PROMPT widget type
- Update Vue component and composable types

Key Features:
- CSV format: word[,priority] compatible with danbooru-tags.txt
- Priority-based sorting: 20% top priority + prefix + include matches
- Preview tooltip for embeddings (not for custom words)
- Dynamic endpoint switching based on prefix detection

Breaking Changes:
- Prompt (LoraManager) node widget type changed from
  AUTOCOMPLETE_TEXT_EMBEDDINGS to AUTOCOMPLETE_TEXT_PROMPT
- Removed standalone web/comfyui/prompt.js (integrated into main widgets)

Fixes comfy_dir path calculation by prioritizing folder_paths.base_path
from ComfyUI when available, with fallback to computed path.

vue-widgets/src/main.ts

@@ -410,7 +410,7 @@ if (app.ui?.settings) {
 function createAutocompleteTextWidgetFactory(
   node: any,
   widgetName: string,
-  modelType: 'loras' | 'embeddings',
+  modelType: 'loras' | 'embeddings' | 'prompt',
   inputOptions: { placeholder?: string } = {}
 ) {
   const container = document.createElement('div')
@@ -529,6 +529,12 @@ app.registerExtension({
       AUTOCOMPLETE_TEXT_EMBEDDINGS(node) {
         const options = widgetInputOptions.get(`${node.comfyClass}:text`) || {}
         return createAutocompleteTextWidgetFactory(node, 'text', 'embeddings', options)
+      },
+      // Autocomplete text widget for prompt (supports both embeddings and custom words)
+      // @ts-ignore
+      AUTOCOMPLETE_TEXT_PROMPT(node) {
+        const options = widgetInputOptions.get(`${node.comfyClass}:text`) || {}
+        return createAutocompleteTextWidgetFactory(node, 'text', 'prompt', options)
       }
     }
   },