feat(worker): auto-tag packages with the slicer(s) their files target

Indexes 86k+ Lychee Slicer (.lys/.lyt), 23k+ ChituBox (.chitubox/.ctb/
.cbddlp), 1k+ Anycubic (.photon/.pwmo/.pwmx), and Bambu (.3mf)
slicer-specific files. Until now they were just generic extensions in
PackageFile.

After this commit:
  - Newly-ingested packages get tags derived from their file list
    ("lychee", "chitubox", "anycubic", "bambu", "fdm", "mango")
  - The `backfill_filelists` listener also applies tags to re-indexed
    packages
  - A new pure-DB listener `backfill_slicer_tags` walks existing
    Packages with file lists and applies tags retroactively — no
    downloads, no TDLib, takes seconds for thousands of rows.

Trigger the one-shot retroactive backfill with:
  SELECT pg_notify('backfill_slicer_tags', '{"limit":5000}');

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

worker/src/worker.ts

@@ -47,6 +47,7 @@ import { pickPreviewFile, extractPreviewImage } from "./preview/extract.js";
 import { groupArchiveSets } from "./archive/multipart.js";
 import type { ArchiveSet } from "./archive/multipart.js";
 import { extractCreatorFromFileName, extractCreatorFromChannelTitle } from "./archive/creator.js";
+import { extractSlicerTags } from "./archive/slicer-tags.js";
 import { hashParts } from "./archive/hash.js";
 import { readZipCentralDirectory } from "./archive/zip-reader.js";
 import { readRarContents } from "./archive/rar-reader.js";
@@ -1730,6 +1731,15 @@ async function processOneArchiveSet(
         tags.push(channel.category);
       }
 
+      // Derive slicer tags from the file listing so users can filter the
+      // catalog by "what software opens these files". Tags include "lychee",
+      // "chitubox", "anycubic", "bambu", "fdm" etc. — only added if matching
+      // slicer-specific files are present in the archive.
+      const slicerTags = extractSlicerTags(entries);
+      for (const tag of slicerTags) {
+        if (!tags.includes(tag)) tags.push(tag);
+      }
+
       stub = await createPackageStub({
         contentHash,
         fileName: archiveName,