v0.6.5

release: v0.6.5 — bump sgr-agent-tui to 0.4.7 with crossterm 0.28

v0.6.4 release CI failed in `cargo publish --verify` because the published
sgr-agent-tui 0.4.6 on crates.io still declared `crossterm = ^0.27`, while
the workspace was bumped to `crossterm 0.28` in bac2d86 without
republishing sgr-agent-tui. When `cargo publish` for rust-code fetched
sgr-agent-tui 0.4.6 from the registry, two crossterm versions ended up
in the dep graph → KeyEvent / MouseEvent type mismatches.

This commit:
* sgr-agent-tui 0.4.6 → 0.4.7 (republished with crossterm 0.28)
* rust-code     0.6.4 → 0.6.5

Publish order: sgr-agent-tui 0.4.7 → crates.io (manual, before tag push),
then v0.6.5 tag triggers CI publish of rust-code.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>