A community based topic aggregation platform built on atproto

refactor(lexicon): remove membership record references

Membership tracking is AppView-only data, not atProto records.

Changes:
- Removed membershipUri field from community.get viewerState
- Updated member field description to clarify it's AppView-computed
- Removed membership lexicon file (already deleted)
- Removed membership test data files (already deleted)

Rationale:
- Membership/reputation is indexed from user activity, not explicit records
- No need for AT-URI reference to non-existent record type
- Clarifies that membership status is computed by AppView, not stored in repo

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Changed files
-12
tests
-6
tests/lexicon-test-data/actor/membership-invalid-reputation.json
···
-
{
-
"$type": "social.coves.actor.membership",
-
"community": "did:plc:examplecommunity123",
-
"createdAt": "2024-01-15T10:30:00Z",
-
"reputation": -50
-
}
-6
tests/lexicon-test-data/actor/membership-valid.json
···
-
{
-
"$type": "social.coves.actor.membership",
-
"community": "did:plc:examplecommunity123",
-
"reputation": 150,
-
"createdAt": "2024-01-15T10:30:00Z"
-
}