Supplement slow-indexed IEEE journals from Crossref (TSE fresh papers)

OpenAlex indexes TSE ~2-3 months late (nothing after 2026-06-26 as of Sep 2),
so TSE never appeared in weekly digests. Sources can now be flagged
crossref_fresh: their recent papers are discovered via Crossref (created-date
window, paper-level CC licence = OA) and listed without abstracts; a digested
paper's missing abstract is filled once OpenAlex indexes the DOI, so a later
--force re-run can add its per-paper summary.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/test_store.py

@@ -38,6 +38,17 @@ def test_upsert_refreshes_undigested_metadata(tmp_path):
         assert paper.abstract == "now with abstract"
 
 
+def test_digested_paper_gains_missing_abstract_but_stays_frozen(tmp_path):
+    with make_store(tmp_path) as store:
+        store.upsert_papers([make_paper("10.1/a", title="fresh via crossref", abstract="")])
+        store.mark_digested(["10.1/a"], WEEK)
+        # OpenAlex later indexes the DOI with an abstract (and a normalised title)
+        store.upsert_papers([make_paper("10.1/a", title="OpenAlex Title", abstract="now indexed")])
+        [paper] = store.pending_papers(WEEK)
+        assert paper.abstract == "now indexed"  # 초록만 보강
+        assert paper.title == "fresh via crossref"  # 그 외 메타데이터는 동결 유지
+
+
 def test_digested_papers_are_frozen_and_skipped(tmp_path):
     with make_store(tmp_path) as store:
         store.upsert_papers([make_paper("10.1/a", title="original")])