Drop garbage uploads early (D42)

Random-named uploads that never get a real name or password were ~90% of
what seeding stores. Two filters:

- before storing (seeding, ingest): random-named uploads of a dropped
  signature (posting tool from the Message-ID, first group) or of a
  release dropped after its probe aren't stored; 2% of a dropped
  signature's releases are still kept and probed. Stored files of dropped
  signatures aren't probed.
- after a probe: a random-named release that is still unnamed, without
  password, names from files or spot, with all its probes done, and
  encrypted, a container or missing its first article, is deleted and
  tombstoned in dropped_releases.

Signatures are learned by gc:scheduler from a sample of probed releases
(signature_probes); garbage:learn --seed fills it from existing files.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/services/ContentService.ts

@@ -25,6 +25,7 @@ import SevenZipService from '#services/SevenZipService'
 import SfvService from '#services/SfvService'
 import ArchiveWalkService from '#services/ArchiveWalkService'
 import { segmentsOf } from '#services/FileStore'
+import GarbageFilter from '#services/GarbageFilter'
 
 /**
  * MD5 of the first 16 KiB of a file, as par2 records it, from the body of
@@ -49,6 +50,8 @@ export interface ContentResult {
   nicovideo?: string
   /** The real name from the yEnc header, for a file posted under a random subject (D36). */
   yencName?: string
+  /** Why the file's release was deleted as garbage after this probe (D42). */
+  garbage?: string
 }
 
 /**
@@ -129,6 +132,8 @@ class ContentService {
   async prepare(fileId: number): Promise<InspectTask | null> {
     const file = await db.from('files').where('id', fileId).first()
     if (!file || !this.isCandidate(file.filename)) return null
+    // Stored before its signature was found to be garbage (D42): not worth an article.
+    if (await GarbageFilter.skipProbe(file)) return null
     if ((sevenZipVolume(String(file.real_name ?? file.filename)) ?? 0) > 1) {
       const volumes = await SevenZipService.volumes(file)
       if (!volumes || volumes[0].archive) return null
@@ -148,8 +153,17 @@ class ContentService {
     }
   }
 
-  /** The database half after a probe: names, groupings, listings and flags from what it found. */
+  /**
+   * The database half after a probe: names, groupings, listings and flags from
+   * what it found. Then the release is deleted if it turned out to be garbage (D42).
+   */
   async apply(task: InspectTask, probe: InspectProbe): Promise<ContentResult> {
+    const result = await this.applyProbe(task, probe)
+    result.garbage = (await GarbageFilter.afterProbe(task.fileId, probe.contentType)) ?? undefined
+    return result
+  }
+
+  private async applyProbe(task: InspectTask, probe: InspectProbe): Promise<ContentResult> {
     const result: ContentResult = { named: 0, contentType: probe.contentType }
     const file = await db.from('files').where('id', task.fileId).first()
     if (!file) return result
@@ -277,6 +291,7 @@ export function describeContent(filename: string, content: ContentResult | null)
   if (content?.contentType === 'nzbe') lines.push(`"${filename}" is an encrypted NZB container.`)
   if (content?.contentType === 'rclone') lines.push(`"${filename}" is rclone-encrypted.`)
   if (content?.yencName) lines.push(`"${filename}" is "${content.yencName}" (yEnc name).`)
+  if (content?.garbage) lines.push(`"${filename}": release deleted as garbage (${content.garbage}, no name or password).`)
   if (content?.nicovideo) lines.push(`"${filename}" → "${content.nicovideo}".`)
   if (content?.sfvMoved) lines.push(`SFV "${filename}" moved ${content.sfvMoved} files into its release.`)
   if (content?.contentType === 'yencbin') lines.push(`"${filename}" is a yEncBin encrypted container.`)