Add test-first-governance preset to the community catalog

[ka-zo]

Description

This PR adds the test-first-governance preset to the community preset catalog and documents it in the community presets table.

What changed

• Added a new entry for the preset in catalog.community.json
• Added a matching entry to presets.md
• Included the preset’s purpose, motivation, and compatibility information in the docs table
• Updated the catalog timestamps for the new entry
• This makes the preset discoverable through the community catalog and gives users a clearer summary of why it exists and what it improves.

Testing

Semantic and Syntactic checking of the following modified files:

• presets\catalog.community.json
• docs\community\presets.md

AI Disclosure

• [] I did not use AI assistance for this contribution
• I did use AI assistance (describe below)

I used GitHub Copilot to double check consistency between my manually added entries in this spec-kit repository and the original repository where the test-first-governance preset is stored.