Fix premature turn completion during tool execution

[BunsDev]

Summary

• Avoid emitting TurnComplete for intermediate tool_use responses so chat mode stays active while Bash/REPL/code tools run.
• Avoid marking recoverable max_tokens continuations as terminal turns.
• Add regression coverage for terminal vs intermediate turn-completion emission.

Test Plan

• git diff --check
• cargo test -p claurst-query --manifest-path src-rust/Cargo.toml

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.