chore: upgrade ai sdk to v6

[uinstinct]

Description

Upgrade aisdk along with corresponding adapters to v6. Also upgrade the functions in packages/openai-adapters to use v6 methods.

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Checklist

• [] I've read the contributing guide
• [] The relevant docs, if any, have been updated or created
• [] The relevant tests, if any, have been updated or created

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Summary by cubic

Upgraded adapters to AI SDK v6, updated tools/messages/streaming to the new API, and switched Anthropic to the native provider for consistent behavior across OpenAI and Anthropic.

• Dependencies

  • ai: ^6.0.86
  • @ai-sdk/openai: ^3.0.29
  • @ai-sdk/anthropic: ^3.0.44

• Refactors

  • Use createAnthropic; remove provider stubs/flags.
  • Map max_tokens → maxOutputTokens; keep stop/top_p behavior.
  • Tools: use inputSchema; enforce top-level object for function params.
  • Messages: assistant tool calls send input (was args); tool results emit output text.
  • Streaming: adopt v6 events (text-/reasoning-start|delta|end with ids; tool-input-start|delta|end); finish uses totalUsage with inputTokens/outputTokens and cache details; ignore start/finish-step/start/abort/raw; update file/source payloads.
  • Usage/embeddings: map inputTokens/outputTokens to OpenAI usage; coerce embed inputs to strings (single and batch).

^{Written for commit ffe90db. Summary will update on new commits.}

[cubic-dev-ai]

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[cubic-dev-ai]

No issues found across 13 files