feat(settings): filename templates for download and bulk rename (#1071)

Add per-model-type filename templates ({model_name}, {version_name},
{base_model}, {author}, {first_tag}, {hash_short}, {original_name}) so
downloaded files get informative names instead of e.g. V1.safetensors.
Empty template keeps the current filename (opt-in, off by default).

- apply template automatically after downloads; rename conflicts keep
  the original name and never fail the download
- record original_file_name in metadata on rename for traceability
- bulk apply via GET|POST /api/lm/{prefix}/apply-filename-template with
  WebSocket progress, sharing the auto-organize lock
- settings UI lives in the new Organization tab with validation, live
  preview, and per-type 'apply to library' actions

static/js/state/index.js

@@ -1,7 +1,7 @@
 // Create the new hierarchical state structure
 import { getStorageItem, getMapFromStorage } from '../utils/storageHelpers.js';
 import { MODEL_TYPES } from '../api/apiConfig.js';
-import { DEFAULT_PATH_TEMPLATES, DEFAULT_PRIORITY_TAG_CONFIG } from '../utils/constants.js';
+import { DEFAULT_PATH_TEMPLATES, DEFAULT_FILENAME_TEMPLATES, DEFAULT_PRIORITY_TAG_CONFIG } from '../utils/constants.js';
 
 const DEFAULT_SETTINGS_BASE = Object.freeze({
     civitai_api_key: '',
@@ -30,6 +30,7 @@ const DEFAULT_SETTINGS_BASE = Object.freeze({
     recipes_path: '',
     base_model_path_mappings: {},
     download_path_templates: {},
+    download_filename_templates: {},
     example_images_path: '',
     example_images_open_mode: 'system',
     example_images_local_root: '',
@@ -74,6 +75,7 @@ export function createDefaultSettings() {
         ...DEFAULT_SETTINGS_BASE,
         base_model_path_mappings: {},
         download_path_templates: { ...DEFAULT_PATH_TEMPLATES },
+        download_filename_templates: { ...DEFAULT_FILENAME_TEMPLATES },
         priority_tags: { ...DEFAULT_PRIORITY_TAG_CONFIG },
         default_other_roots: {},
         enabled_other_sub_types: ['vae', 'upscaler', 'text_encoder'],