Add Tempest -- Tauri-based ADE with 64% fewer tokens

[gsvprharsha]

Summary

Adds Tempest to the Session managers & parallel runners section, sorted by stars (15) between Garcon (43 stars) and showagent (37 stars).

Checklist:

• Has a terminal interface: embedded xterm.js for running CLI coding agents
• Reads/writes code and runs commands autonomously via hosted agents (Claude Code and others)
• Active project with public GitHub repo
• Entry format: name + link, star count, 1-2 line description, license
• Placed in correct star-sorted position