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.

py/routes/misc_routes.py

@@ -18,6 +18,7 @@ from ..services.settings_manager import get_settings_manager
 from ..services.downloader import get_downloader
 from ..utils.usage_stats import UsageStats
 from .handlers.misc_handlers import (
+    CustomWordsHandler,
     FileSystemHandler,
     HealthCheckHandler,
     LoraCodeHandler,
@@ -117,6 +118,7 @@ class MiscRoutes:
             service_registry=self._service_registry_adapter,
             metadata_provider_factory=self._metadata_provider_factory,
         )
+        custom_words = CustomWordsHandler()
 
         return self._handler_set_factory(
             health=health,
@@ -129,6 +131,7 @@ class MiscRoutes:
             model_library=model_library,
             metadata_archive=metadata_archive,
             filesystem=filesystem,
+            custom_words=custom_words,
         )