Tighten BugBot releasability and dependency rules

[willccbb]

Description

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Test improvement

Testing

• All existing tests pass when running uv run pytest locally.
• New tests have been added to cover the changes

Checklist

• My code follows the style guidelines of this project as outlined in AGENTS.md
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published

Additional Notes

---

Note

Low Risk
Low risk: changes are limited to reviewer instructions and license text, with no runtime or behavioral code modifications.

Overview
Strengthens .cursor/BUGBOT.md review criteria by explicitly requiring PRs to leave the repo in a releasable state (no hidden failures, skipped checks, or post-merge cleanup) and by rejecting dependency specs that pin to GitHub sources.

Updates LICENSE to change the copyright notice to 2026 Prime Intellect and fixes the missing trailing newline.

^{Reviewed by Cursor Bugbot for commit ab5f86e. Bugbot is set up for automated code reviews on this repo. Configure here.}