add anthropic messages parameter test cases

[knjiang]

Add Anthropic Messages API parameter test cases to the existing params.ts file for cross-provider mapping coverage.

New test coverage, got the request body from https://docs.anthropic.com/en/api/messages:

Category	OpenAI (existing)	Anthropic (new)
Reasoning	effort, summary	+ thinking (enabled/disabled, budget_tokens)
Tools	function, web_search, code_interpreter, tool_choice	✓ web_search_20250305, bash_20250124, + text_editor (v1/v2/v3), tool_choice (auto/any/none/tool)
Tool config	parallel_tool_calls	✓ disable_parallel_tool_use
Context	instructions, system message	✓ system
Caching	service_tier, prompt_cache_key	✓ service_tier, + cache_control (ephemeral, ttl: 5m/1h)
Metadata	metadata, safety_identifier	✓ metadata, metadata.user_id
Sampling	temperature, top_p, frequency_penalty, presence_penalty	✓ temperature, top_p, + top_k
Output control	stop, max_completion_tokens	✓ stop_sequences, max_tokens
Streaming	-	+ stream
Content types	-	+ image (base64), document (text)
Web search config	-	+ allowed_domains, max_uses, user_location

cross compatability coverage report -> https://github.com/braintrustdata/lingua/actions/runs/21009331032

[knjiang]

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• add anthropic messages parameter test cases #59 👈 (View in Graphite)
• add chat completion parameter test cases #58
• add openai responses parameter test cases #54
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