Adopt upstream #3031: hook - emit ask decision for Claude rewrites #2

Adopt rtk-ai/rtk#3031 by @houtinghang. Triage rank 1.

Default-to-ask path lost rewrites in the Claude hook; root-caused with regression tests for both modes, fixes upstream rtk-ai#3018. Supersedes duplicate PRs rtk-ai#2571 / rtk-ai#3012 — reference, do not also adopt.

Adoption checklist (per CONTEXT.md)

• Sync: git merge upstream/develop into develop
• Repro the bug on pre-cherry-pick binary
• Cherry-pick preserving authorship; confirm fixed behavior with real output in the PR
• Quality gate: cargo fmt --all && cargo clippy --all-targets && cargo test --all
• Amendments (if needed) as separate fork-authored commits