Promotion: MIT license, MCP registry metadata, submission copy, release rule update

Switch from TEC Friendly License to MIT for better ecosystem recognition
(Glama, GitHub, awesome-lists). Add server.json for MCP registry, SUBMISSIONS.md
with ready-to-paste copy for all platforms, stars badge to README, and update
github-release rule to prepend project intro on future releases.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>