Rename blocklists to IP lists, add IP lookup flags, raise the download limit to 200 MiB (closes #233)

The lists are not only used for blocking, so the package, the `blocklists` field of the IP lookup answer and the state directory are now IP lists (`internal/iplist`, `ip_lists`, `iplists`). Every result gains a `flags` object with `is_tor` and `is_bogon`. The largest list file accepted is 200 MiB.

Judgement call: the dated 2026-10-27 `TODO.md` entry keeps the old word.
Rule suppressed: `tagliatelle` on the two result structs, for snake_case keys.

Model: opus-5-5

internal/iplist/lists.go

@@ -0,0 +1,96 @@
+package iplist
+
+import "time"
+
+// TorExitsList is the name of the list of Tor exit nodes.
+const TorExitsList = "tor_exits"
+
+// How often each list is downloaded. No list is downloaded more often than
+// its publisher updates it or allows.
+const (
+	// DShield asks that its feeds be downloaded at most once an hour:
+	// https://isc.sans.edu/feeds_doc.html
+	dshieldInterval = time.Hour
+
+	// abuse.ch makes the list every 5 minutes and recommends a download at
+	// least every 15: https://feodotracker.abuse.ch/blocklist/
+	feodoTrackerInterval = 15 * time.Minute
+
+	// FireHOL's page for each list gives how often the list changes on
+	// average: about every 5 hours for abusers and every 3 hours for level
+	// 3. FireHOL sets no download limit.
+	// https://iplists.firehol.org/?ipset=firehol_abusers_30d
+	// https://iplists.firehol.org/?ipset=firehol_level3
+	fireHOLAbusersInterval = 5 * time.Hour
+	fireHOLLevel3Interval  = 3 * time.Hour
+
+	// Spamhaus asks that DROP be downloaded at most once a day:
+	// https://www.spamhaus.org/blocklists/do-not-route-or-peer/
+	spamhausDROPInterval = 24 * time.Hour
+
+	// Tor publishes a new exit list every hour and sets no download limit:
+	// https://collector.torproject.org/recent/exit-lists/
+	torExitsInterval = time.Hour
+)
+
+// Lists returns the public IP lists routewatch downloads. Each can be
+// downloaded whole without an account or a key. Spamhaus merged its EDROP
+// list into DROP, so DROP covers both.
+func Lists() []List {
+	return []List{
+		{
+			Name: "dshield",
+			Description: "In one of the 20 networks that DShield saw scan " +
+				"the most targets in the last three days",
+			URL:      "https://feeds.dshield.org/block.txt",
+			Interval: dshieldInterval,
+			Format:   FormatDShield,
+		},
+		{
+			Name:        "feodo_tracker",
+			Description: "A botnet command-and-control server",
+			URL:         "https://feodotracker.abuse.ch/downloads/ipblocklist.txt",
+			Interval:    feodoTrackerInterval,
+			Format:      FormatLines,
+		},
+		{
+			Name: "firehol_abusers_30d",
+			Description: "Reported for comment, form or forum spam in the " +
+				"last 30 days",
+			URL:      "https://iplists.firehol.org/files/firehol_abusers_30d.netset",
+			Interval: fireHOLAbusersInterval,
+			Format:   FormatLines,
+		},
+		{
+			Name: "firehol_level3",
+			Description: "Reported for attacks, spyware or viruses in the " +
+				"last 30 days",
+			URL:      "https://iplists.firehol.org/files/firehol_level3.netset",
+			Interval: fireHOLLevel3Interval,
+			Format:   FormatLines,
+		},
+		{
+			Name: "spamhaus_drop",
+			Description: "In an IPv4 network that Spamhaus says spammers " +
+				"or cyber criminals have hijacked or lease",
+			URL:      "https://www.spamhaus.org/drop/drop_v4.json",
+			Interval: spamhausDROPInterval,
+			Format:   FormatSpamhausJSON,
+		},
+		{
+			Name: "spamhaus_dropv6",
+			Description: "In an IPv6 network that Spamhaus says spammers " +
+				"or cyber criminals have hijacked or lease",
+			URL:      "https://www.spamhaus.org/drop/drop_v6.json",
+			Interval: spamhausDROPInterval,
+			Format:   FormatSpamhausJSON,
+		},
+		{
+			Name:        TorExitsList,
+			Description: "A Tor exit node, where traffic from the Tor network leaves",
+			URL:         "https://check.torproject.org/torbulkexitlist",
+			Interval:    torExitsInterval,
+			Format:      FormatLines,
+		},
+	}
+}