Part 2 of #2260. **Builds on #2261** (certain liveness): review/merge
that first; until then this diff also shows its commit.
## Adaptive offline threshold
`userManagement.notifications.adaptiveOffline` — **off by default**:
```json
"notifications": {
"enabled": true,
"adaptiveOffline": { "enabled": true, "floorMinutes": 30, "minObservers": 3 }
}
```
The fixed `infraSilentHours` (72 h) treats every repeater the same. With
this on, a watched node's `node.offline` window is learned from its own
**certain** traffic (the #2261 rule):
1. Certain packets per hour over the week **before its last certain
packet**. Ending there, not at now, keeps an outage from dragging the
rate down until the fixed window returns and the node reads "back
online".
2. Empty runs are classified: ≤ 6 h and recurring on another day at the
same hours = normal silence (kept; the window is never shorter than the
longest + 1 h); any other run = outage, left out of the learning so it
neither stretches the window nor blocks learning.
3. λ = 10th percentile of the remaining hourly counts, so quiet nights
don't alert.
4. Window = 14/λ hours: silence at rate λ has a < 10⁻⁶ chance (Poisson,
ln 10⁶ ≈ 13.8).
5. Clamped to [`floorMinutes`, the role's silent window].
Kept on the fixed window: λ < 1/hour, under 24 h of history in memory,
or a 10th-percentile hour heard by fewer than `minObservers` observers
(one observer dropping out must not read as the node going offline).
Silence is measured up to the newest packet in the store, so a stalling
feed stops every node's clock. A node stored offline comes back only on
evidence from the moment it went offline on. The notifier caches each
learned window for 10 minutes and drops unwatched nodes.
For the #2260 repeater (~840 packets/day) the mail would have gone out
about 30 minutes into the outage, instead of never (or 72 h with #2261
alone).
## Certain node analytics
- Each `activityTimeline` bucket carries `certain`: the part that can
only be this node (`certainFor`, the packet-level form of the
`certainHeard` rule). `TimeBucket.Certain` is `omitempty`, so other
endpoints are unchanged.
- Availability and longest silence use certain buckets only; the longest
silence now includes one **still running** (an outage in progress is the
silence worth seeing).
- The chart stacks certain (`--accent`) and uncertain (`--text-muted`) —
existing theme variables, so no new customizer entry. Descriptions
updated.
## Performance
`CertainActivity` walks a week of packets per watched node, at most once
per node per 10 minutes, with the read lock taken **per node**:
```
BenchmarkCertainActivity-16 12.1 ms/op (50 watched repeaters × 6,000 packets; ~0.25 ms per lock hold)
BenchmarkNoteCertainRelays-16 121 ns/op 0 allocs
```
Node analytics adds one `certainFor` per packet of the requested node (a
prefix-map lookup, or the cached decoded JSON for its own packets).
## Tests
- `adaptiveOfflineAfter`: busy repeater hits the floor; 5/hour; quiet
nights set the rate; > 10 % empty hours, short history, too few
observers → fixed.
- `CertainActivity` ends at the last certain packet and counts only
certain packets — verified red by mutating the window to end at now.
- Notifier end to end: learned window passed → bad; inside → good; too
few observers / setting off → fixed 72 h; cache refresh and prune.
- `certainFor`, `longestSilence` (incl. running silence), config
defaults, `/api/nodes/{pk}/analytics` splits a shared-prefix bucket.
- Frontend: `NodeAnalyticsTimeline.series` (new
`tests/unit/test-node-analytics-certain-timeline.js`).
- `cmd/server` `go test ./...` and `test-all.sh` pass locally, also on a
trial merge into a downstream fork.
## Validation
Server on the freshened e2e fixture: analytics buckets carry `certain`
(e.g. 89 of 90 packets certain for one repeater). **No browser
screenshot**: Playwright isn't installed on this machine.
## Later (rule 8)
`floorMinutes` / `minObservers` are server config, not theme settings;
an admin UI for notification settings would be the place, not the
customizer.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
