## What
The Route Patterns chart on `/#/analytics` ignored the Time window
picker — every selection returned identical data. This PR threads
`?window=` through to the backing endpoints and the store-level
computation.
## Root cause
`cmd/server/routes.go:2065` (`handleAnalyticsSubpaths`) and
`cmd/server/routes.go:2090` (`handleAnalyticsSubpathsBulk`) never called
`ParseTimeWindow(r)`. The store-level entry points
(`GetAnalyticsSubpaths`, `GetAnalyticsSubpathsBulk`) had no window-aware
variant. The frontend (`public/analytics.js`) didn't append `&window=`
to the `/analytics/subpaths-bulk` request.
## Fix
### Backend (`cmd/server/store.go`)
Added `GetAnalyticsSubpathsWithWindow` +
`GetAnalyticsSubpathsBulkWithWindow`. Zero `TimeWindow` →
byte-equivalent to the existing fast path (no perf regression on the
default view). Non-zero window → iterate `s.packets`, filter on
`tx.FirstSeen` via `TimeWindow.Includes`, reuse `rankSubpaths`. Cached
by `(region|area|window)`.
```diff
-data := s.store.GetAnalyticsSubpaths(region, minLen, maxLen, limit)
+window := ParseTimeWindow(r)
+data := s.store.GetAnalyticsSubpathsWithWindow(region, minLen, maxLen, limit, window)
```
```diff
-results := s.store.GetAnalyticsSubpathsBulk(region, groups)
+results := s.store.GetAnalyticsSubpathsBulkWithWindow(region, groups, ParseTimeWindow(r))
```
### Frontend (`public/analytics.js`)
`renderSubpaths` now appends `&window=<value>` to the
`/analytics/subpaths-bulk` request, matching how RF / topology /
channels tabs already wire the picker.
## Before / after
```
GET /api/analytics/subpaths?window=24h → totalPaths=2 (all data — ignored window)
GET /api/analytics/subpaths?window=24h → totalPaths=1 (24h-bounded — honored)
```
## Tests
`cmd/server/subpaths_window_test.go`:
- `TestSubpathsHonorsTimeWindow_StoreLevel` — seeds a 1h-old tx with
path `[aa,bb]` + a 30d-old tx with path `[cc,dd]`; asserts the unbounded
call sees both and the 24h-windowed call sees only the recent one.
- `TestSubpathsHandlerHonorsTimeWindow` — same scenario via the HTTP
handlers for `/api/analytics/subpaths` and
`/api/analytics/subpaths-bulk`.
TDD: red commit `eefc27d3` (test fails on assertion with stub that
ignores window), green commit `4c4c45d0` (implementation makes it pass).
Full `go test ./...` in `cmd/server` green locally (~47s).
## Performance
Default view (no window selected) is unchanged — `window.IsZero()`
short-circuits to the existing precomputed-index hot path. Windowed view
is O(N_tx · path²), same complexity as the existing region-filtered slow
path. Results cached per `(region|area|window)`.
Closes#1217
---------
Co-authored-by: Kpa-clawbot <bot@corescope>
