feat(dir): add optional trust ranking reference extension

[leocharny]

Summary

This PR adds a reference-only trust ranking PoC as an optional extension.

It is intentionally:

• additive (no core behavior changes)
• non-authoritative
• not a security system or standard

The goal is to provide a concrete artifact for discussion around
how trust-related signals could influence discovery and ranking.

What’s included

• A minimal trust ranking interface (extensions/trust_ranking/interface.py)
• A toy reference implementation with explainable output
• Sample data (examples/directory_sample.json) and a CLI runner (scripts/run_trust_ranking.py)
• Basic unit tests (stdlib unittest)
• Documentation clarifying scope and limitations (extensions/trust_ranking/REFERENCE.md)
• Small root README hook pointing to the reference doc

What’s not included

• No protocol changes
• No server-side enforcement
• No governance or policy assumptions

Feedback welcome.

[leocharny]

Cleaned up formatting-only diffs and opened a new PR with a minimal, focused diff. Thanks for the suggestion.

[ramizpolic]

Hi @leocharny, thanks for the submission!

Regarding community meetings, we have weekly Dir meetings every Thursday (link to calendar: https://calendar.google.com/calendar/u/0/[email protected]). We can have a quick demo (5 mins if enough) with a follow-up discussion on this topic.

[leocharny]

Hi @ramizpolic thanks for the invite.
A 5-minute demo this Thursday meeting works for me. Happy to do a short walkthrough and take follow-up questions.