feat(blacklist): add per-topic text deny-list with whitelist exceptions

Six public commands let any member of a chat curate two lists of text and
ask whether a given text is blocked: /blacklist_add, /blacklist_del,
/whitelist_add, /whitelist_del, /blacklist_rules and /blacklist_check.

The module is passive. It never reads ordinary chat messages and never
deletes, warns or restricts anyone; the lists stay inert until
/blacklist_check asks about a specific text.

Scope is one forum topic, keyed (Chat.ID, MessageThreadID) and gated on
IsTopicMessage so a reply chain in a plain supergroup does not become its
own unreachable scope. A plain group, a DM and a forum's General topic all
resolve to one chat-wide list.

Matching is substring, after NFKC composition, case folding and whitespace
collapse. Diacritics stay significant, so ma, má and mà are three entries.
A whitelist entry rescues a blacklist match only when it spans that match,
which is what keeps "I met an assassin, dumbass" blocked.

Entry text is percent-encoded before it becomes a storage key, since keys
forbid '/' and cap at 1500 bytes, and is capped at 200 bytes before and
after normalization because NFKC can expand as well as contract.

/blacklist_rules reads each list with Scan, so listing costs one round trip
per list rather than a Get per entry.

cmd/server/command_menu_test.go

@@ -75,6 +75,12 @@ func TestCommandDiscovery_AllPublicCommandsHaveSafeMetadata(t *testing.T) {
 		"addsticker":           "[emoji...]",
 		"alias":                "<name>",
 		"aliases":              "",
+		"blacklist_add":        "[text...]",
+		"blacklist_del":        "<text...>",
+		"blacklist_rules":      "",
+		"blacklist_check":      "<text...>",
+		"whitelist_add":        "[text...]",
+		"whitelist_del":        "<text...>",
 		"unalias":              "<name>",
 		"insert":               "<name>",
 		"stats":                "[users | user <username> | cmd <command_name>]",

cmd/server/main.go

@@ -20,6 +20,7 @@ import (
 	"github.com/tiennm99/miti99bot/internal/modules"
 	"github.com/tiennm99/miti99bot/internal/modules/alias"
 	"github.com/tiennm99/miti99bot/internal/modules/amlich"
+	"github.com/tiennm99/miti99bot/internal/modules/blacklist"
 	"github.com/tiennm99/miti99bot/internal/modules/coin"
 	"github.com/tiennm99/miti99bot/internal/modules/gold"
 	"github.com/tiennm99/miti99bot/internal/modules/lol"
@@ -95,6 +96,7 @@ func factories() map[string]modules.Factory {
 		"stats":                stats.New,
 		sticker.CollectionName: sticker.New,
 		"alias":                alias.New,
+		"blacklist":            blacklist.New,
 	}
 }
 

cmd/server/main_test.go

@@ -128,3 +128,34 @@ func TestFactoriesIncludesExpectedModules(t *testing.T) {
 		}
 	}
 }
+
+func TestFactoriesRegistersBlacklistCommands(t *testing.T) {
+	catalog := factories()
+	if catalog["blacklist"] == nil {
+		t.Fatal("factories missing blacklist")
+	}
+	reg, err := modules.Build([]string{"blacklist"}, catalog, storage.NewMemoryProvider(), modules.BuildOptions{})
+	if err != nil {
+		t.Fatalf("Build blacklist: %v", err)
+	}
+	for _, name := range []string{
+		"blacklist_add", "blacklist_del", "blacklist_rules", "blacklist_check",
+		"whitelist_add", "whitelist_del",
+	} {
+		if _, ok := reg.AllCommands[name]; !ok {
+			t.Fatalf("missing command %s", name)
+		}
+	}
+	if got := len(reg.AllCommands); got != 6 {
+		t.Fatalf("blacklist registered %d commands, want 6", got)
+	}
+}
+
+// An empty MODULES loads every module, so a command name that collides with an
+// existing module surfaces here as a test failure rather than as a startup
+// crash on deploy.
+func TestFactoriesBuildWholeCatalog(t *testing.T) {
+	if _, err := modules.Build(nil, factories(), storage.NewMemoryProvider(), modules.BuildOptions{}); err != nil {
+		t.Fatalf("Build whole catalog: %v", err)
+	}
+}