Spotnet import, header backfill, staging and counter grouping, faster search

Spotnet (CONCEPT D29):
- Index free.pt fully and import spots with their descriptions, categories
  and NZBs; a spot renames its release, since Spotnet names are more
  trustworthy than names derived from subjects.
- Find passwords in spot descriptions too, and tell "needs a password we
  have" from "needs a password we don't have".

Content inspection:
- List the contents of 7z (.7z.001) archives, SFV sets, nicovideo uploads
  and other archive-like files; mark yEncBin .bin containers as encrypted.
- Take real names from yEnc headers for randomly named files, and merge
  uploads that were split across posts.

Storage (D31, D32):
- Store segment lists zstd-compressed behind the FileStore accessor.
- group:backfill indexes older headers at low priority and pauses when
  the NVMe or HDD part of the database gets too large.

Grouping (D35, D36):
- Lone header segments wait in staged_segments until a second segment of
  their file arrives, which drops the per-article junk binaries.
- Counter grouping joins random-subject uploads by poster, [i/M] counter,
  part count and day.

Search and maintenance (D33, D34):
- A trigram-indexed search_text column, smaller indexes, estimated stats.
- Passes that clean up nonsense names; weekly index maintenance; GC budgets
  per kind.
- Web UI: grey out stale results while a search runs and cancel superseded
  requests. Count only up to 1,000 matches for the page, which made filter
  clicks take seconds (Newznab keeps the 10,000 cap).

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

lib/newznab/xml.ts

@@ -13,6 +13,8 @@ export interface NewznabItem {
   poster: string | null
   groups: string[]
   password: boolean
+  /** Longer text than the title, e.g. a Spotnet spot's description (UBB markup). */
+  description?: string
   season?: string
   episode?: string
 }
@@ -26,6 +28,16 @@ export interface NewznabServer {
 }
 
 /** Newznab error codes: 100 credentials, 200/201 parameters, 202 function, 300 item. */
+/** Spotnet UBB markup (or the HTML of old spots) as plain text: [br] as line breaks, other tags dropped. */
+export function ubbToText(ubb: string): string {
+  return ubb
+    .replace(/<br\s*\/?>|\[br\]/gi, '\n')
+    .replace(/<\/?[a-z][^>]*>/gi, '')
+    .replace(/\[url=([^\]]*)\]([\s\S]*?)\[\/url\]/gi, (_, url: string, label: string) => (label.trim() ? `${label} (${url.trim()})` : url.trim()))
+    .replace(/\[\/?[a-z]+(?:=[^\]]*)?\]/gi, '')
+    .trim()
+}
+
 export function errorXml(code: number, description: string): string {
   return create({ version: '1.0', encoding: 'UTF-8' })
     .ele('error', { code: String(code), description })
@@ -74,7 +86,7 @@ export function resultsXml(server: NewznabServer, items: NewznabItem[], offset:
     element.ele('comments').txt(`${server.baseUrl}/?release=${item.id}`)
     element.ele('pubDate').txt(pubDate)
     element.ele('category').txt(categoryLabel(item.category))
-    element.ele('description').txt(item.title)
+    element.ele('description').txt(item.description ? ubbToText(item.description) : item.title)
     element.ele('enclosure', { url: getUrl, length: String(item.size), type: 'application/x-nzb' })
 
     const attr = (name: string, value: string | number) =>