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- Web UI: grey out stale results while a search runs and cancel superseded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>

tests/unit/sevenzip.spec.ts

@@ -0,0 +1,71 @@
+import { test } from '@japa/runner'
+import {
+  checkHeader,
+  listingStart,
+  parseBsdtarListing,
+  parseSevenZipStart,
+  readNumber,
+  sevenZipVolume,
+} from '#lib/sevenzip/index'
+
+// `7z a tiny.7z Tiny.Release` (Tiny.Release/a.txt): an LZMA-encoded header.
+const ENCODED = Buffer.from(
+  'N3q8ryccAATeIVLCfQAAAAAAAAAhAAAAAAAAAGkLW/MBAAtoZWxsbyB3b3JsZAoAAACBMweuD87ysgwHyEN/QbH6/duIttdfpOXRhZbi6t7tycGOUDyW1l2aTE7xmuZ/NAXKgg599VxKYAF1XImsfT9LzHQKaEH6PEZambLnwJM62mXXEJIpaYvhCrHFeQv+jLnYjgJMfwZEcAAAABcGEAEJbQAHCwEAASMDAQEFXQAQAAAMgJYKASTou9wAAA==',
+  'base64'
+)
+// The same with -mhc=off: a plain header.
+const PLAIN = Buffer.from(
+  'N3q8ryccAASpRwRsEAAAAAAAAACWAAAAAAAAACTou9wBAAtoZWxsbyB3b3JsZAoAAQQGAAEJEAAHCwEAASEhAQAMDAAICgEtOwivAAAFAg4BgBkJAAAAAAAAAAAAEUEAVABpAG4AeQAuAFIAZQBsAGUAYQBzAGUAAABUAGkAbgB5AC4AUgBlAGwAZQBhAHMAZQAvAGEALgB0AHgAdAAAABkCAAAUEgEA/QYYLBBR3QH9BhgsEFHdARUKAQAQgP1BIIC0gQAA',
+  'base64'
+)
+
+test.group('sevenzip', () => {
+  test('finds the header at the end from the signature header', ({ assert }) => {
+    const start = parseSevenZipStart(ENCODED)!
+    assert.deepEqual(start, { headerStart: 157, headerSize: 33, headerCrc: start.headerCrc, archiveSize: 190 })
+    const header = ENCODED.subarray(start.headerStart, start.archiveSize)
+    assert.isTrue(checkHeader(start, header))
+    assert.isFalse(checkHeader(start, Buffer.alloc(33)))
+    // Encoded: the packed header right after the file data (packPos 16) is needed too.
+    assert.equal(listingStart(start, header), 48)
+
+    const plain = parseSevenZipStart(PLAIN)!
+    assert.equal(plain.archiveSize, PLAIN.length)
+    assert.equal(listingStart(plain, PLAIN.subarray(plain.headerStart)), plain.headerStart)
+  })
+
+  test('rejects other data and a damaged signature header', ({ assert }) => {
+    assert.isNull(parseSevenZipStart(Buffer.from('Rar!\x1a\x07\x01\x00'.padEnd(40, '\0'), 'latin1')))
+    const damaged = Buffer.from(ENCODED)
+    damaged[14] ^= 1
+    assert.isNull(parseSevenZipStart(damaged))
+  })
+
+  test('reads 7z numbers', ({ assert }) => {
+    assert.deepEqual(readNumber(Buffer.from([0x10]), 0), [16, 1])
+    assert.deepEqual(readNumber(Buffer.from([0x81, 0x02]), 0), [0x102, 2])
+    assert.deepEqual(readNumber(Buffer.from([0xc0, 0x34, 0x12]), 0), [0x1234, 3])
+    assert.deepEqual(readNumber(Buffer.from([0xff, 1, 0, 0, 0, 0, 0, 0, 0]), 0), [1, 9])
+  })
+
+  test('parses bsdtar listings', ({ assert }) => {
+    const out = [
+      'drwxrwxr-x  0 0      0           0 Sep 30 19:13 Some.Release.2026/',
+      '-rw-rw-r--  0 0      0     3000000 Sep 30 19:13 Some.Release.2026/movie.mkv',
+      '-rw-rw-r--  0 0      0           3 Jan  1  2019 Some.Release.2026/some info.nfo',
+      '',
+    ].join('\n')
+    assert.deepEqual(parseBsdtarListing(out), [
+      { name: 'Some.Release.2026', size: 0, directory: true },
+      { name: 'Some.Release.2026/movie.mkv', size: 3000000, directory: false },
+      { name: 'Some.Release.2026/some info.nfo', size: 3, directory: false },
+    ])
+  })
+
+  test('numbers volumes', ({ assert }) => {
+    assert.equal(sevenZipVolume('x.7z.001'), 1)
+    assert.equal(sevenZipVolume('X.7Z.012'), 12)
+    assert.equal(sevenZipVolume('x.7z'), 0)
+    assert.isNull(sevenZipVolume('x.part01.rar'))
+  })
+})