Rebuild: NZBs from the chunk store, and a catalog search

lib/nzb (buildNzb, parseNzb) from the current app; NzbService builds a
release's NZB from its chunks; GET /api/v1/releases?q= (every word of the
name) and GET /api/v1/releases/:id/nzb behind the api guard. A test stores
a batch, finds the release and reads its NZB back.

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

lib/nzb/build.ts

@@ -0,0 +1,56 @@
+import { create } from 'xmlbuilder2'
+/** One article of a file: its number, message-id (without <>) and size in bytes. */
+export interface Segment {
+  number: number
+  id: string
+  size: number
+}
+
+export interface NzbFile {
+  /** Name the downloader should use; the real name when it is known. */
+  name: string
+  poster: string
+  /** Posting time in milliseconds. */
+  date: number
+  groups: string[]
+  segments: Segment[]
+}
+
+export interface NzbOptions {
+  /** Shown by downloaders as the job name. */
+  title?: string
+  /** Archive password, when known. */
+  password?: string
+}
+
+/**
+ * Builds an NZB 1.1 document (newzbin DTD). The subject follows the common
+ * `"name" yEnc (1/N)` form, which downloaders use to name the file.
+ */
+export function buildNzb(files: NzbFile[], options: NzbOptions = {}): string {
+  const root = create({ version: '1.0', encoding: 'UTF-8' })
+    .dtd({ pubID: '-//newzBin//DTD NZB 1.1//EN', sysID: 'http://www.newzbin.com/DTD/nzb/nzb-1.1.dtd' })
+    .ele('nzb', { xmlns: 'http://www.newzbin.com/DTD/2003/nzb' })
+
+  if (options.title || options.password) {
+    const head = root.ele('head')
+    if (options.title) head.ele('meta', { type: 'name' }).txt(options.title)
+    if (options.password) head.ele('meta', { type: 'password' }).txt(options.password)
+  }
+
+  for (const file of files) {
+    const sorted = [...file.segments].sort((a, b) => a.number - b.number)
+    const element = root.ele('file', {
+      poster: file.poster,
+      date: String(Math.floor(file.date / 1000)),
+      subject: `"${file.name}" yEnc (1/${sorted.length})`,
+    })
+    const groups = element.ele('groups')
+    for (const group of file.groups) groups.ele('group').txt(group)
+    const segments = element.ele('segments')
+    for (const segment of sorted) {
+      segments.ele('segment', { bytes: String(segment.size), number: String(segment.number) }).txt(segment.id)
+    }
+  }
+  return root.end({ prettyPrint: true })
+}