fix(ingest): D-04 bibkey heuristic + D-05a/b/c regression tests + __main__

D-04: add _make_bibkey(paper) — ConcatSurnames+Year, ≤3 authors full list,
      >3 authors FirstEtAlYear. Applied in ingest_paper when paper.bibkey is
      None. ON CONFLICT now fills NULL bibkeys via COALESCE(papers.bibkey,
      EXCLUDED.bibkey) while preserving manually-set values.

D-05b: add codex/__main__.py so `python -m codex` dispatches to the CLI.

D-05c: fix test_ingest.py:75 — rename var to raw_api_citations (the raw
       OpenAlex payload with citing_id=openalex_id) and add regression
       assertion: citing_id written to DB must equal paper.id (DOI), not
       paper.openalex_id.

D-05a (proxy): add TestEntryPoint.test_python_m_codex_help — runs
       `sys.executable -m codex --help` via subprocess, covering the
       non-uv-run entry path. 253 tests green, ruff+mypy clean.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

codex/__main__.py

@@ -0,0 +1,3 @@
+from codex.cli import app
+
+app()

codex/ingest.py

@@ -27,6 +27,25 @@ class IngestResult:
     figures_upserted: int = 0
 
 
+def _make_bibkey(paper: Paper) -> str | None:
+    """Generate a BibTeX-style key from paper metadata.
+
+    Format: ConcatSurnames + Year (e.g. "BobenkoPinkallSpringborn2015").
+    Surnames are the last whitespace-separated token of each author name.
+    >3 authors: FirstSurname + "EtAl" + Year.
+    Returns None when authors or year are missing.
+    """
+    if not paper.authors or not paper.year:
+        return None
+    surnames = [name.split()[-1] for name in paper.authors if name.strip()]
+    if not surnames:
+        return None
+    year = str(paper.year)
+    if len(surnames) <= 3:
+        return "".join(surnames) + year
+    return surnames[0] + "EtAl" + year
+
+
 def ingest_paper(
     paper_id: str,
     source_path: str | None = None,
@@ -61,6 +80,7 @@ def ingest_paper(
     # ---------------------------------------------------------------
     paper: Paper | None = openalex.fetch_paper(paper_id)
 
+
     if paper is None:
         # Detect arXiv IDs: numeric pattern like "2301.07041" or "arxiv:..." prefix
         pid_lower = paper_id.lower()
@@ -78,6 +98,10 @@ def ingest_paper(
     if paper is None:
         raise ValueError(f"Paper not found: {paper_id}")
 
+    # Auto-generate bibkey when source has none (D-04).
+    if paper.bibkey is None:
+        paper.bibkey = _make_bibkey(paper)
+
     # ---------------------------------------------------------------
     # 2. Embed abstract (dense only — schema has one vector column)
     # ---------------------------------------------------------------
@@ -102,6 +126,7 @@ def ingest_paper(
                     %(abstract)s, %(source_path)s, %(abstract_emb)s)
             ON CONFLICT (id) DO UPDATE SET
                 openalex_id  = EXCLUDED.openalex_id,
+                bibkey       = COALESCE(papers.bibkey, EXCLUDED.bibkey),
                 title        = EXCLUDED.title,
                 authors      = EXCLUDED.authors,
                 year         = EXCLUDED.year,
@@ -181,7 +206,10 @@ def ingest_paper(
             raw = openalex.fetch_citations(paper.openalex_id)
             # OpenAlex returns citing_id=openalex_id, but papers.id uses the DOI.
             # Rewrite citing_id to paper.id so the FK constraint is satisfied.
-            api_citations = [Citation(citing_id=paper.id, cited_id=c.cited_id, context=c.context) for c in raw]
+            api_citations = [
+                Citation(citing_id=paper.id, cited_id=c.cited_id, context=c.context)
+                for c in raw
+            ]
         else:
             api_citations = semanticscholar.fetch_references(paper_id)