fix CI release version sync and remove dead tmux capture code

[TomCC7]

Summary

• sync Cargo.toml package version from v* tag in release workflow before cargo-dist steps to avoid stale-manifest release failures
• limit npm publish workflow trigger scope to release tags and add a dedicated stale automation workflow via actions/stale@v10
• remove unused tmux_capture_pane implementation and related tests that had no production call sites and caused cargo test failures

Verification

• cargo test
• cargo build
• workflow YAML parsing for modified files

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!