Rolling store-path data (never pin)

Rolling assets: overwritten in place by the hourly and weekly jobs, so
nothing may ever hash-pin them. Everything here is an advisory overlay
or reproducible observation — keyed, self-contained data whose staleness
degrades to "no speedup", never to a wrong answer.

• tip-outpaths.json: (attr, version) -> digest for the versions current
  at the newest indexed revision; rewritten as the channel moves.
• misses.json: the pairs the matcher could not resolve, for diagnosis.
• census.json (weekly): the liveness census snapshot.
• graph.jsonl.gz (hourly, once seeded): the narinfo crawl state the
  incremental jobs resume from.