Annotate Text-to-Speech models with metadata attributes (~118 models)

[ooples]

Context

Sub-issue of #958 (Annotate all model classes with metadata attributes)

Scope

Annotate all concrete model classes in src/TextToSpeech/ with the 6 model metadata attributes.

Subdirectories (~118 models)

• CodecBased/ (~32 models)
• Vocoders/ (~16 models) - BigVGAN, HiFiGAN, Vocos, etc.
• Classic/ (~15 models) - Tacotron2, etc.
• MultiModal/ (~10 models)
• ProprietaryAPI/ (~9 models)
• VoiceCloning/ (~9 models)
• FlowDiffusion/ (~8 models) - MatchaTTS, etc.
• Latest/ (~7 models)
• Remaining subdirectories

Acceptance Criteria

• Every concrete model class has all required attributes
• dotnet build src/AiDotNet.csproj --framework net10.0 -c Release passes with 0 errors
• No model class in src/TextToSpeech/ is missed

[ooples]

All 121 text-to-speech model classes annotated with metadata attributes.

[ooples]

All Text-to-Speech model classes are in src/Audio/TextToSpeech/ and were already annotated as part of the Audio module (closed in #977). 9 TTS model files confirmed annotated. No additional work needed.

[ooples]

All concrete model classes in scope are annotated. Completed in PR #965.