Town: one report for several runs

A village and the pair runs (Hollo, Iceshrimp.NET, Pleroma) are checked
apart; town.sh report takes them together and adds their cells up, so one
matrix shows every server.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

CLAUDE.md

@@ -532,6 +532,7 @@ tools/pasture/town.sh selftest [peer...]   # each driver against its own server;
 tools/pasture/town.sh seed village         # specs/village.json: 23 accounts on seven servers, about 11 minutes
 tools/pasture/town.sh check village        # out/<run>/results.json; --deadline=0 re-sweeps an old run at once
 tools/pasture/town.sh report village       # out/<run>/report.html, publishable (fake data, no tokens)
+tools/pasture/town.sh report village hollo-pair iceshrimp-pair pleroma-pair   # several runs in one matrix
 tools/pasture/town.sh backlog --write      # docs/INTEROP-BACKLOG.md
 ```