feat: add Voice Design node + language and guidance_scale to Generate

OmniVoiceVoiceDesign: structured dropdowns for gender/age/pitch/accent
that compose into an instruct string — wire to Generate's instruct input.

OmniVoiceGenerate: new optional language dropdown (auto + 11 languages)
and guidance_scale (CFG, default 2.0) parameters.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

__init__.py

@@ -1,4 +1,4 @@
-from .nodes import OmniVoiceModelLoader, OmniVoiceGenerate, OmniVoiceEpubLoader, OmniVoiceVoicePreset, OmniVoiceMixVoices
+from .nodes import OmniVoiceModelLoader, OmniVoiceGenerate, OmniVoiceEpubLoader, OmniVoiceVoicePreset, OmniVoiceMixVoices, OmniVoiceVoiceDesign
 
 NODE_CLASS_MAPPINGS = {
     "OmniVoiceModelLoader": OmniVoiceModelLoader,
@@ -6,6 +6,7 @@ NODE_CLASS_MAPPINGS = {
     "OmniVoiceEpubLoader": OmniVoiceEpubLoader,
     "OmniVoiceVoicePreset": OmniVoiceVoicePreset,
     "OmniVoiceMixVoices": OmniVoiceMixVoices,
+    "OmniVoiceVoiceDesign": OmniVoiceVoiceDesign,
 }
 
 NODE_DISPLAY_NAME_MAPPINGS = {
@@ -14,6 +15,7 @@ NODE_DISPLAY_NAME_MAPPINGS = {
     "OmniVoiceEpubLoader": "OmniVoice EPUB Loader",
     "OmniVoiceVoicePreset": "OmniVoice Voice Preset",
     "OmniVoiceMixVoices": "OmniVoice Mix Voices",
+    "OmniVoiceVoiceDesign": "OmniVoice Voice Design",
 }
 
 __all__ = ["NODE_CLASS_MAPPINGS", "NODE_DISPLAY_NAME_MAPPINGS"]