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

The answers of GeoJS, the lists fetched by URL, the DNS blocklists,
AbuseIPDB and routewatch each go in a cache file in SWW_CACHE_DIR
(default /var/cache/sww): lookups.json, lists.json, dnsbl.json,
abuseipdb-scores.json and routewatch.json. reputation.json is gone. The
AbuseIPDB checks spent today are a count, not a cache, and stay in
SWW_STATE_DIR as abuseipdb-checks-spent.json.

A cache file never stops the start: one that does not parse is set
aside as an edit is, one that cannot be read is written over, and its
cache starts empty. An unwritable SWW_CACHE_DIR stops the start, as an
unwritable SWW_STATE_DIR does. Each directory is watched on its own.
The run script makes the cache directory and gives it to sww.

Model: opus-5-5

internal/reputation/crowdsec_test.go

@@ -291,7 +291,7 @@ func crowdSecFailures() []crowdSecFailure {
 // other than its decision list, such as the one a redirect names, and that
 // the key is in none of what the fetches leave behind: log, the process
 // log, the alerts waiting in queue, and the copies of lists, which
-// reputation.json keeps.
+// lists.json keeps.
 func wantKeyNotShown(
 	t *testing.T, e *engine, log string, lists *reputation.Lists, queue *alerts.Queue,
 ) {
@@ -326,7 +326,7 @@ func TestCrowdSecDecisionListKeptAcrossARestartEndsWhenItsDecisionsDo(t *testing
 		lists := start(t, e, crowdSecParams())
 		kept := lists.Snapshot()
 
-		// Restarted half an hour later with what reputation.json keeps, and
+		// Restarted half an hour later with what lists.json keeps, and
 		// the engine down, the decision still bans, until the end it had at
 		// the fetch, half an hour on.
 		time.Sleep(30 * time.Minute)