Caches of outside APIs live in /var/cache/sww (closes #314)

Every cache of answers from an outside service has its own file in `SWW_CACHE_DIR` (default `/var/cache/sww`): `lookups.json` (GeoJS), `lists.json` (lists fetched by URL, CrowdSec's decisions included), `dnsbl.json`, `abuseipdb-scores.json` and `routewatch.json` (at most 100,000 answers, each kept an hour). `reputation.json` is gone; the AbuseIPDB checks spent today stay in `SWW_STATE_DIR` as `abuseipdb-checks-spent.json`, since losing them would spend the daily budget twice.

A cache file never stops the start: one that does not parse is set aside as `<name>.bad` with a `file_error` alert. An unwritable `SWW_CACHE_DIR` stops the start. The `run` script creates the cache directory and gives it to `sww`. The cache directory needs no volume and can be left out of backups.

Model: opus-5-5

internal/reputation/reputation_test.go

@@ -260,7 +260,7 @@ func TestKeptCopyIsFetchedAgainOnceRefreshHasPassedSinceItWasFetched(t *testing.
 		lists.SetTransport(servers)
 
 		// drop.txt was fetched an hour ago, and tor.txt a refresh ago, as
-		// reputation.json says at start.
+		// lists.json says at start.
 		err := lists.Load([]reputation.List{
 			{URL: dropURL, Fetched: time.Now().Add(-time.Hour), Lines: []string{"203.0.113.9"}},
 			{URL: torURL, Fetched: time.Now().Add(-refresh), Lines: []string{"198.51.100.9"}},
@@ -297,7 +297,7 @@ func TestRestartWaitsRefreshAfterTheLastTryEvenOneThatFailed(t *testing.T) {
 		time.Sleep(refresh)
 		wantFetches(t, servers, 2)
 
-		// Restarted with what reputation.json keeps, it waits a refresh
+		// Restarted with what lists.json keeps, it waits a refresh
 		// after the failed try, as it does while it runs.
 		restarted := &standIn{lists: map[string]string{dropURL: "198.51.100.2\n"}}
 		again := reputation.New(params(dropURL))
@@ -353,7 +353,7 @@ func TestFetchCutOffAsItStopsIsNoFailureButARestartWaitsForIt(t *testing.T) {
 				waiting(queue))
 		}
 
-		// Restarted an hour later with what reputation.json keeps, it fetches
+		// Restarted an hour later with what lists.json keeps, it fetches
 		// tor.txt, never tried, at once, and drop.txt a refresh after its
 		// cut-off try.
 		time.Sleep(time.Hour)