Add a decision for opt-in breaking changes

[zastrowm]

Add a record of the decision that "opt-in breaking changes" being acceptable from an SDK evolution strategy.

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[strands-agent]

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[mehtarac]

/strands review

[github-actions]

Assessment: Approve ✅

This decision record is well-written and follows the established structure in DECISIONS.md.

Key Observations:

• Structure is consistent with prior decisions (Date, Decision, Rationale sections)
• The "pay for play" principle is clearly explained with a concrete TypedDict example
• Good balance of explaining when the policy applies vs. when it doesn't apply
• External reference to Raymond Chen's post provides additional context

The updated example (addressing pgrayy's feedback) now clearly distinguishes between the producing side vs. reading side of the breaking change, making the concept more understandable.

Nice addition to the decision record! 🎉

[strands-agent]

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[strands-agent]

Documentation Deployment Complete

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Preview URL: https://d3ehv1nix5p99z.cloudfront.net/pr-491/