Settings tabs, log overlay, external URL, Sources tree restructure, audio fixes

- Settings modal split into 3 tabs: General, Backup, MQTT
- Log viewer moved to full-screen overlay with compact toolbar
- External URL setting: API endpoints + UI for configuring server domain
  used in webhook/WS URLs instead of auto-detected local IP
- Sources tab tree restructured: Picture Source (Screen Capture/Static/
  Processed sub-groups), Color Strip, Audio, Utility
- TreeNav extended to support nested groups (3-level tree)
- Audio tab split into Sources and Templates sub-tabs
- Fix audio template test: device picker now filters by engine type
  (was showing WASAPI indices for sounddevice templates)
- Audio template test device picker disabled during active test
- Rename "Input Source" to "Source" in CSS test preview (en/ru/zh)
- Fix i18n: log filter/level items deferred to avoid stale t() calls

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/src/wled_controller/static/locales/zh.json

@@ -316,6 +316,12 @@
   "settings.tab.backup": "备份",
   "settings.tab.mqtt": "MQTT",
   "settings.logs.open_viewer": "打开日志查看器",
+  "settings.external_url.label": "外部 URL",
+  "settings.external_url.hint": "设置后，此基础 URL 将用于 webhook 链接和其他用户可见的链接，代替自动检测的本地 IP。示例：https://myserver.example.com:8080",
+  "settings.external_url.placeholder": "https://myserver.example.com:8080",
+  "settings.external_url.save": "保存",
+  "settings.external_url.saved": "外部 URL 已保存",
+  "settings.external_url.save_error": "保存外部 URL 失败",
   "settings.general.title": "常规设置",
   "settings.capture.title": "采集设置",
   "settings.capture.saved": "采集设置已更新",
@@ -447,6 +453,7 @@
   "streams.group.css_processing": "处理模板",
   "streams.group.color_strip": "色带源",
   "streams.group.audio": "音频",
+  "streams.group.audio_templates": "音频模板",
   "streams.section.streams": "源",
   "streams.add": "添加源",
   "streams.add.raw": "添加屏幕采集",
@@ -1113,7 +1120,7 @@
   "color_strip.type.processed": "已处理",
   "color_strip.type.processed.desc": "将处理模板应用于另一个源",
   "color_strip.type.processed.hint": "包装现有色带源并通过滤镜链处理其输出。",
-  "color_strip.processed.input": "输入源：",
+  "color_strip.processed.input": "源：",
   "color_strip.processed.input.hint": "将被处理的色带源",
   "color_strip.processed.template": "处理模板：",
   "color_strip.processed.template.hint": "应用于输入源输出的滤镜链",
@@ -1276,11 +1283,20 @@
   "audio_template.error.delete": "删除音频模板失败",
   "streams.group.value": "值源",
   "streams.group.sync": "同步时钟",
+  "tree.group.picture": "图片源",
   "tree.group.capture": "屏幕采集",
+  "tree.group.static": "静态",
   "tree.group.processing": "已处理",
-  "tree.group.picture": "图片",
   "tree.group.strip": "色带",
+  "tree.group.audio": "音频",
   "tree.group.utility": "工具",
+  "tree.leaf.sources": "源",
+  "tree.leaf.engine_templates": "引擎模板",
+  "tree.leaf.images": "图片",
+  "tree.leaf.video": "视频",
+  "tree.leaf.filter_templates": "滤镜模板",
+  "tree.leaf.processing_templates": "处理模板",
+  "tree.leaf.templates": "模板",
   "value_source.group.title": "值源",
   "value_source.select_type": "选择值源类型",
   "value_source.add": "添加值源",