docs: update versioning to v0.7.0 and document new features

[Classic298]

• Standardize versioning from 0.7 to 0.7.0 across all guides and Docker tags
• Update Knowledge Base tool documentation with new query_knowledge_files and query_knowledge_bases (metadata search) tools
• Add documentation for the new Model Activity Chart in Evaluations
• Add WHISPER_MULTILINGUAL env var and update WHISPER_VAD_FILTER configuration details

[pr-validator-bot]

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