Add cross-channel spam tracker; refactor detection

Introduce a rapidSpamTracker to detect same messages posted across channels within a short window and return prior message IDs for cleanup. Refactor spam detection to collect scannable text from message content, embeds and attachments, simplify role-ping and link heuristics, and mark spam when a role ping + link is duplicated across channels. Update index to use the tracker/collector, delete prior spam messages, improve moderation flow (ban → kick fallback), report clearer action/error labels, and warn about missing channel permissions. Update commands display text for detection/actions and bump .env.example MIN_ACCOUNT_AGE_DAYS default to 7.

Anti-Spam/src/rapidSpamTracker.js

@@ -0,0 +1,46 @@
+const WINDOW_MS = 150_000; // 2.5 minutes
+const recentPosts = new Map();
+
+function normalizeKey(text) {
+  return text.toLowerCase().replace(/\s+/g, " ").trim().slice(0, 200);
+}
+
+export function trackCrossChannelMessage(guildId, userId, channelId, messageId, text) {
+  const normalized = normalizeKey(text);
+  if (!normalized) {
+    return { duplicateAcrossChannels: false, priorMessages: [] };
+  }
+
+  const key = `${guildId}:${userId}:${normalized}`;
+  const now = Date.now();
+  const existing = recentPosts.get(key);
+
+  if (existing && now - existing.firstSeen < WINDOW_MS) {
+    const priorMessages = [...existing.messages.entries()].map(([chId, msgId]) => ({
+      channelId: chId,
+      messageId: msgId,
+    }));
+
+    existing.channels.add(channelId);
+    existing.messages.set(channelId, messageId);
+
+    const duplicateAcrossChannels = existing.channels.size >= 2;
+    return { duplicateAcrossChannels, priorMessages: duplicateAcrossChannels ? priorMessages : [] };
+  }
+
+  recentPosts.set(key, {
+    channels: new Set([channelId]),
+    messages: new Map([[channelId, messageId]]),
+    firstSeen: now,
+  });
+
+  if (recentPosts.size > 5000) {
+    for (const [entryKey, entry] of recentPosts) {
+      if (now - entry.firstSeen > WINDOW_MS) {
+        recentPosts.delete(entryKey);
+      }
+    }
+  }
+
+  return { duplicateAcrossChannels: false, priorMessages: [] };
+}