feat: show compact System version history with plain update copy

[caigee-cmd]

Summary

• Add a compact System-page version history: one release open at a time, notes in a short scrolling box, current/latest badges, and restore limited to the three previous stable releases.
• Replace Docker-jargon update copy with operator-facing steps: download the update, tap Update now, then refresh after a short countdown.
• Include recent GitHub releases in the update check payload so the console can show history without dumping the full list.
• Clarify Models-page defaults: Trae Max is a larger context window, not a plan or quota, and reasoning intensity is a fallback when the request omits it.

This is a console UX change only. It does not bump or publish a new patch release.

Test plan

• Open System and confirm the history accordion defaults to the latest release when an update exists, otherwise the current version.
• Expand another version and confirm only one panel stays open, with notes scrolling inside the compact box.
• Download an update, confirm the button becomes Update now, then after apply confirm the countdown refresh copy.
• Restore one of the three previous versions from history and confirm the confirmation dialog still uses the existing rollback path.
• Open Models and confirm Trae Max is labeled as larger context, with a tooltip that it is a default unless the request sets is_max_mode.
• Confirm reasoning intensity has a visible label/tooltip saying it does not lock every call, and Details uses localized level names.