feat: add spam detection lane (tower.classify.spam) with content-aware filtering

- Add SpamJobData + sync missing job types (DncJobData, ClassifyJobData, P1JobData, etc.) from dist back to source in @tower/types
- spam-detector.ts: emoji-only, short-greeting, link-only detection + duplicate-hash (1h window)
- spam.queue.ts / spam.processor.ts: BullMQ tower.classify.spam lane
- classify.processor.ts: spam check (Step 0) before rule engine, accepts spamQueue param
- main.ts: wire spamQueue + spamWorker; spam pre-filter before ingestQueue.add
- dnc.processor.ts: labelled reason logging

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/types/src/message.ts

@@ -91,4 +91,72 @@ export interface IndexJobData {
   tags: string[];
   platform: string;
   approvedAt: string;      // ISO 8601 — converted to Unix ms in the index processor
+  traceId?: string;
+}
+
+export interface DncJobData {
+  tenantId: string;
+  sourceGroupId: string;
+  accountId: string;
+  reason: 'rule_skip' | 'no_rule_match' | 'spam_detected' | 'content_filtered';
+  timestamp: string;
+  policyVersion: string;
+  traceId?: string;
+}
+
+export interface ClassifyJobData {
+  messageId: string;
+  tenantId: string;
+  sourceGroupId: string;
+  sourceGroupJid: string;
+  senderJid: string;
+  accountId: string;
+  traceId?: string;
+}
+
+export interface ThreadResolveJobData {
+  messageId: string;
+  tenantId: string;
+  sourceGroupId: string;
+  quotedPlatformMsgId?: string;
+  traceId?: string;
+}
+
+export interface DigestJobData {
+  tenantId: string;
+  digestDate: string;
+  triggeredBy: 'schedule' | 'manual';
+  traceId?: string;
+}
+
+export interface ReviewJobData {
+  tenantId: string;
+  messageId: string;
+  sourceGroupId: string;
+  tags: string[];
+  reason: string;
+  policyVersion: string;
+  traceId?: string;
+}
+
+export interface P1JobData {
+  tenantId: string;
+  messageId: string;
+  content: string;
+  sourceGroupId: string;
+  senderJid: string;
+  senderName?: string;
+  tags: string[];
+  policyVersion: string;
+  traceId?: string;
+}
+
+export interface SpamJobData {
+  tenantId: string;
+  messageId: string;
+  sourceGroupId: string;
+  senderJid: string;
+  reason: 'forward_flood' | 'duplicate_hash' | 'emoji_only' | 'short_greeting' | 'link_only';
+  contentHash: string;
+  traceId?: string;
 }