Terminal polish and Windows reliability

Tightens terminal output handling around ANSI escapes and UTF-8 boundaries, makes the Windows Codex hook more resilient, and adds crash-reporting and slow-path telemetry to catch regressions earlier.

• Cleaner terminal output. Large pastes and high-throughput agent output no longer split inside escape sequences or surrogate pairs, so colors, hyperlinks, and emoji render cleanly after trims and replays.
• Windows Codex hook resilience. Rebuilt the Codex notification hook in cmd-native form so it no longer chokes on quoting or stale multi-line notify entries in the Codex config.
• Better crash reporting. Sentry now initializes the renderer directly from the host so we catch errors that previously slipped past the auto-injector, with tighter filters to keep the signal clean.