feat(aws-bedrock): update model YAMLs [bot]

[hganwani-droid]

Auto-generated by poc-agent for provider aws-bedrock.

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Note

Medium Risk
Updates model capability and limit metadata plus removes tiered_pricing overrides, which can affect token limit enforcement and cost calculations for this Bedrock model. Risk is moderate because it changes configuration used for routing/validation/billing, but is scoped to a single model YAML.

Overview
Updates the jp.anthropic.claude-sonnet-4-6 AWS Bedrock model config by removing tiered_pricing blocks from the regional cost entries and expanding declared capabilities (adds system_messages, tool_choice, caching-related features, and assistant_prefill).

Bumps limits from 200k to 1M for context_window/max_input_tokens, adds tool_use_system_prompt_tokens, and refines modalities to explicitly include text I/O.

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