M7: daily rollups

A RollupDay job folds each finished day's InteractionEvents into one InstanceDay per server:
- Counters for the admin, keyed channel:activity:object:outcome:reason, plus signature
  schemes, audiences, local kinds and features;
- PublicCounters, everything a public page may ever read:
  - inbound and outbound activities from an allowlist, on public, unlisted or unaddressed
    traffic only, with the outcome collapsed (accepted or dropped, delivered or failed);
  - no reasons, no Flag or Block;
  - features of public objects;
  - health:ok or health:failed from reachability (a 4xx means the server answered);
- latency, wait and byte histograms, and the number of distinct accounts from that day's
  hashes.

Re-running a day replaces it and keeps the live Reads counters. The day's salt is then
deleted, so its hashes can never be recomputed, and the next day is queued.
StatisticsSchedule plans today's rollup every hour and catches up any of the last seven
days that have events but no rollup. Waits round up into their bucket.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ELjqpznMFMNrJoJUj6K5p2

PrivaPub/Models/Jobs/Job.cs

@@ -26,7 +26,8 @@ namespace PrivaPub.Models.Jobs
 		DescribeInstance,
 		PollRefresh,
 		PollClose,
-		FetchPreview
+		FetchPreview,
+		RollupDay
 	}
 
 	public enum JobState