Issue #147: Delete should remove match from both sides

Summary

When one party deletes a conversation, the match should be completely removed from both sides, not just the deleter's side. This allows users to re-nect if they meet again.

Current Behavior

1. ELI nects REA → REA accepts → Match created
2. REA deletes conversation
3. REA's conversation is removed ✅
4. ELI receives notification "This person ended the conversation" ✅
5. ELI still shows CHAT button on Connect screen ❌
6. ELI cannot re-nect REA (no NECT button available)

Expected Behavior

1. ELI nects REA → REA accepts → Match created
2. REA deletes conversation
3. REA's conversation is removed ✅
4. ELI receives notification "This person ended the conversation" ✅
5. ELI's match card is removed from Connect screen ✅
6. ELI sees NECT button if REA is still visible nearby ✅
7. ELI can re-nect REA if desired

Why This Matters

• User expectation: If someone ends a conversation, the relationship is over from both sides
• Re-connection flow: Users should be able to start fresh after a delete
• Consistency: The "ended" notification implies the match is over, but the CHAT button suggests it's still active
• E2E Test: Scenario 16b (Re-nect after REAL delete) fails because of this behavior

Technical Details

When processing a delete notification from the other party:

1. Show the "This person ended the conversation" message ✅ (already done)
2. Remove the match from local database (new)
3. Remove the person's card from Connect screen nearbyPeople list (new)
4. If the person is still broadcasting nearby, they should appear as a new beacon with NECT button

Related

• Discovered during E2E test scenario 16b
• Similar to how messaging apps handle blocks/unfriends