Add Anthropic reasoning capture and release 0.9.4

[antoinezambelli]

Summary

Forge 0.9.4 adds native Anthropic tool-call reasoning capture for both direct client use and Forge Proxy.

Anthropic thinking blocks and streaming thinking_delta content now enter Forge's existing ToolCall.reasoning carrier. Structured thinking takes precedence over the existing visible-text fallback, and the existing reasoning_replay policy controls exposure and replay.

Native signed Anthropic thinking-block round-tripping remains outside this release's scope.

Closes #152.

Changes

• Capture plaintext Anthropic thinking blocks in non-streaming tool-call responses.
• Accumulate thinking_delta content in streaming tool-call responses.
• Prefer native thinking over visible preamble text while preserving the existing text fallback.
• Attach shared reasoning only to the first tool call.
• Preserve text-only response behavior.
• Exercise OpenAI-caller/Anthropic-backend Proxy responses in buffered and streaming modes.
• Update the reasoning-replay decision record for the new Anthropic behavior.
• Bump Forge/PyPI and the standalone Proxy stable pointer to 0.9.4.

Validation

• Full unit suite: 1,545 passed, 1 skipped
• Disposable 0.9.4 wheel and sdist built successfully
• Both artifacts passed twine check
• Wheel and sdist inventories inspected; expected Anthropic implementation and release metadata are present
• No eval JSONL, Parquet, node_modules, build-output, environment, credential, or token files found in either artifact
• git diff --check: clean

The Windows x64, Linux x64/glibc, and macOS ARM64 Proxy candidate jobs and aggregate candidate remain required before merge. Their retained bytes will be promoted through the normal post-merge release process.

Release

• Operation: proxy-release
• Forge/PyPI version: 0.9.4
• Standalone Proxy pointer: 0.9.4
• Hugging Face dataset publication: none

Generated with Codex and human-reviewed.