Langfuse v4.25.0 defines a normalized I/O contract and starts enforcing historical data access limits on the API

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Released 2026-08-31, Langfuse v4.25.0 lands a normalized I/O contract with projections (#16216) and a Kysely base for the ClickHouse query AST (#16687), the groundwork for querying traces without per-integration shape handling. It also enforces historical data access limits on the API (#16760) and reframes the in-app migration headline around a compatibility deadline (#16776), so self-hosters on older versions have a clock running. On the eval side, MCP now describes evaluator output definitions (#16816) and evaluator samples filter by dataset name (#16799).