v1.7.2: Panel resize & TUI stability

What changed

• Panel toggle no longer shrinks terminal rows — fixed multiple resize race conditions that caused line loss when opening or closing the bottom panel
• TUI app stability — sync-output apps like htop and vim now maintain correct dimensions during panel and sidebar transitions
• What's New panel — post-update feature discovery via a StatusBar chip and slide-out panel so you never miss new features
• Error explanation improvements — auto-dismiss stale cards, archive and restore dismissed explanations, scroll-to-error from history
• WSL cursor offset fix — resize-on-connect and updated estimation constants eliminate cursor misalignment on Windows Subsystem for Linux
• LLM crash prevention — serialized native LLM access prevents exit-code-3 crashes when multiple error explanations trigger simultaneously
• Minimap rendering fix — cleared shadow-blur residue that left artifacts at the bottom edge of the minimap canvas
• Free-tier AI enforcement — Neuro Agent sessions now correctly respect free-tier usage limits