feat(workers): extract.pdf with Tesseract fallback

pdftotext first; falls back to per-page pdftoppm rasterization +
Tesseract OCR when the extracted text is < 200 chars. Updates
refs.body_text + metadata.extract.{method,chars} via the repo shim;
audit entry emitted with actor_kind='worker'.

born_digital.pdf fixture padded so pdftotext yields > 200 chars and
the test exercises the pdftotext path, not the OCR fallback.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

workers/tests/test_pdf.py

@@ -0,0 +1,58 @@
+import subprocess
+from pathlib import Path
+from void_workers.handlers.pdf import handle as handle_pdf
+
+FIXTURES = Path(__file__).parent / "fixtures"
+
+
+def _run_node_migrations():
+    subprocess.run(
+        ["node", "lib/db/migrate.js", "up"],
+        cwd="/project/src/void-v2",
+        check=True
+    )
+
+
+def _reset_void_schema(conn):
+    """Mirror tests/helpers/db.js::resetDb on the Node side."""
+    conn.execute("DROP SCHEMA IF EXISTS public CASCADE")
+    conn.execute("CREATE SCHEMA public")
+    conn.execute("CREATE EXTENSION IF NOT EXISTS pgcrypto")
+    conn.execute("CREATE EXTENSION IF NOT EXISTS vector")
+
+
+def _seed_space_and_ref(conn, blob_path, kind="pdf"):
+    sp = conn.execute(
+        "INSERT INTO spaces(slug, name) VALUES('plan4-tests', 'P4') "
+        "ON CONFLICT (slug) DO UPDATE SET name=EXCLUDED.name RETURNING id"
+    ).fetchone()[0]
+    ref = conn.execute(
+        "INSERT INTO refs(space_id, kind, source_url, title, blob_path) "
+        "VALUES(%s, %s, NULL, 'fixture', %s) RETURNING id",
+        (sp, kind, str(blob_path))
+    ).fetchone()[0]
+    return sp, ref
+
+
+def test_pdf_born_digital_uses_pdftotext(conn):
+    _reset_void_schema(conn)
+    _run_node_migrations()
+    blob = FIXTURES / "born_digital.pdf"
+    sp, ref = _seed_space_and_ref(conn, blob)
+    out = handle_pdf({"ref_id": str(ref), "blob_path": str(blob)})
+    assert out["ref_id"] == str(ref)
+    assert out["method"] == "pdftotext"
+    assert out["chars"] > 0
+    row = conn.execute("SELECT body_text FROM refs WHERE id=%s", (ref,)).fetchone()
+    assert "void-workers" in (row[0] or "").lower()
+
+
+def test_pdf_scanned_falls_back_to_tesseract(conn):
+    _reset_void_schema(conn)
+    _run_node_migrations()
+    blob = FIXTURES / "scanned.pdf"
+    sp, ref = _seed_space_and_ref(conn, blob)
+    out = handle_pdf({"ref_id": str(ref), "blob_path": str(blob)})
+    assert out["method"] == "tesseract"
+    row = conn.execute("SELECT body_text FROM refs WHERE id=%s", (ref,)).fetchone()
+    assert "blackflame" in (row[0] or "").lower()