A peer catch-up cohort with substance on two facets:

• Google ADK 1.5.0 + genai 2.15.0: the new Part.audioTranscription field is carried whole via provider-raw (nothing silently dropped when native-audio models transcribe), and CompactedEvent gains a projection + event-level provider-raw ledger for session-replay tolerance.
• Vercel AI 7.0.51: empty text-deltas carrying a providerMetadata bag now emit text.delta with the first-class metadata slot — the Reducer merges it onto the sealed block. Scoped to empty deltas so existing output stays byte-identical.
• The ai/@ai-sdk/mcp lockstep repair: both pin @ai-sdk/provider-utils exactly; mismatched pairs install duplicate copies whose unique-symbol-branded Schema breaks typecheck. This cohort aligned the pairing and documented the ladder — the compatibility tables now record which combinations are verified.
• Claude Agent SDK 0.3.221 and OpenAI Agents 0.14.2 verified as wire no-ops.