fix(llm): empty-text items are stamped as final and count toward docket completion (refs #615)

Treating a blank load() as unindexable defeated the feature it was
meant to protect: four of the eleven historical dockets hold 1-2
comments with no text at all, so none of them could ever be marked
complete and ~130k items would be re-listed on every run.

An item with no text is a finished state, not a failure. Stamp it into
index_state with content_hash='' / chunk_count=0 and its fingerprint —
the empty hash cannot collide with a real sha256 — so the next run
fingerprint-skips it without a load, and it no longer blocks its
docket's completion. Text appearing later changes the fingerprint and
the item is embedded normally.

Only a ref that loaded *with* text and chunked to nothing stays
unindexable and blocks index_docket_state; the embed/write path already
aborts the whole run on error. The index_state upsert both callers need
is now _record_state().

src/llm/index.py

@@ -101,6 +101,32 @@ def _delete_old_chunks(engine: Engine, item_key: str, collection: str) -> None:
         log.debug("langchain_pg_embedding not present yet; skipping delete")
 
 
+def _record_state(
+    engine: Engine, key: str, collection: str, h: str, n: int, fingerprint: str
+) -> None:
+    """Upsert this item's row in ``index_state``.
+
+    ``h == "" and n == 0`` is the *stamped-final* form: an item with no
+    text at all. It is a finished state, not a failure — no chunks exist
+    to delete or embed — and the empty hash can never collide with a real
+    ``content_hash`` (a sha256 hexdigest), so the next run recognises it
+    by fingerprint alone and never loads it again. If text does appear
+    later the fingerprint changes and the item is embedded normally.
+    """
+    with engine.begin() as conn:
+        conn.execute(
+            text(
+                "INSERT INTO index_state "
+                "(item_key, collection, content_hash, chunk_count, fingerprint) "
+                "VALUES (:k, :c, :h, :n, :f) "
+                "ON CONFLICT (item_key, collection) DO UPDATE SET "
+                "content_hash = :h, chunk_count = :n, fingerprint = :f, "
+                "indexed_at = now()"
+            ),
+            {"k": key, "c": collection, "h": h, "n": n, "f": fingerprint},
+        )
+
+
 def index_refs(
     refs: Iterable[DocRef],
     *,
@@ -117,14 +143,19 @@ def index_refs(
     Per ref: (1) fingerprint equal to the stored one → skip without
     loading; (2) load, hash the text; hash equal → record the new
     fingerprint, skip embedding; (3) chunk, locate PDF pages, embed,
-    write. PDFs are opened only on path (3). After the loop, a docket in
-    *sealed* is recorded in ``index_docket_state`` — so the next run does
-    not list it at all — only when every one of its refs was accounted
-    for: a ref that loaded blank or produced no chunks is *unindexable*
-    and blocks completion, because a seal must never claim coverage this
-    run did not achieve. *mark_complete* False (a ``--limit`` run is
-    never complete) blocks it too. Pass *engine* to reuse a caller's
-    engine instead of building a second one.
+    write. PDFs are opened only on path (3). A ref that loads blank is
+    *stamped final* (see :func:`_record_state`) rather than treated as a
+    failure — plenty of real comments carry no text at all.
+
+    After the loop, a docket in *sealed* is recorded in
+    ``index_docket_state`` — so the next run does not list it at all —
+    only when every one of its refs was accounted for. A ref that loaded
+    *with* text but chunked to nothing is *unindexable* and blocks
+    completion, because a seal must never claim coverage this run did not
+    achieve (an exception on the embed/write path aborts the run and so
+    blocks it too). *mark_complete* False (a ``--limit`` run is never
+    complete) blocks it as well. Pass *engine* to reuse a caller's engine
+    instead of building a second one.
     """
     engine = engine if engine is not None else _engine(cfg)
     migrate(engine)
@@ -156,7 +187,8 @@ def index_refs(
             continue
         doc = ref.load()
         if doc is None or not doc.text.strip():
-            _unindexable(ref)
+            _record_state(engine, ref.key, collection, "", 0, ref.fingerprint)
+            stats["skipped"] += 1
             continue
         h = content_hash(doc.text)
         if not force and prev_hash == h:
@@ -182,24 +214,7 @@ def index_refs(
             metadatas=[c.metadata for c in chunks],
             ids=[c.id for c in chunks],
         )
-        with engine.begin() as conn:
-            conn.execute(
-                text(
-                    "INSERT INTO index_state "
-                    "(item_key, collection, content_hash, chunk_count, fingerprint) "
-                    "VALUES (:k, :c, :h, :n, :f) "
-                    "ON CONFLICT (item_key, collection) DO UPDATE SET "
-                    "content_hash = :h, chunk_count = :n, fingerprint = :f, "
-                    "indexed_at = now()"
-                ),
-                {
-                    "k": ref.key,
-                    "c": collection,
-                    "h": h,
-                    "n": len(chunks),
-                    "f": ref.fingerprint,
-                },
-            )
+        _record_state(engine, ref.key, collection, h, len(chunks), ref.fingerprint)
         stats["indexed"] += 1
         stats["chunks"] += len(chunks)
         # needs 100+ docs in one run to hit this line

tests/llm/test_index_refs.py

@@ -32,6 +32,13 @@ def _ref(fp="fp1", docket="D", loads=None, doc=DOC):
     )
 
 
+def _maybe_chunk_doc(fn):
+    """Patch llm.index.chunk_doc only when a test asks for it."""
+    from contextlib import nullcontext
+
+    return nullcontext() if fn is None else patch("llm.index.chunk_doc", side_effect=fn)
+
+
 def _run(
     refs,
     state_rows,
@@ -40,7 +47,7 @@ def _run(
     sealed=None,
     mark_complete=True,
     complete_rows=(),
-    chunks_for=lambda d, c: c,
+    chunk_doc=None,
 ):
     store = MagicMock()
     engine = MagicMock()
@@ -63,8 +70,9 @@ def _run(
         patch("llm.index.vectorstore", return_value=store),
         patch("llm.index.embed_texts", return_value=[[0.0] * 3]),
         patch("llm.index.ensure_hnsw"),
-        patch("llm.index.enrich_pdf_pages", side_effect=chunks_for) as enrich,
+        patch("llm.index.enrich_pdf_pages", side_effect=lambda d, c: c) as enrich,
         patch("llm.index.HostPool") as MockPool,
+        _maybe_chunk_doc(chunk_doc),
     ):
         MockPool.return_value.check.return_value = ["http://h1:11434"]
         stats = index_refs(
@@ -152,30 +160,59 @@ def test_not_marked_when_mark_complete_false_or_unsealed():
     assert stats["docket_complete"] == 0
 
 
-def test_sealed_docket_not_marked_when_a_ref_is_unindexable():
-    """A docket with an item that has no indexable text is not complete."""
+def _state_inserts(conn):
+    return [
+        c
+        for c in conn.execute.call_args_list
+        if "INSERT INTO index_state" in str(c.args[0])
+    ]
+
+
+def _docket_inserts(conn):
+    return [
+        c
+        for c in conn.execute.call_args_list
+        if "INSERT INTO index_docket_state" in str(c.args[0])
+    ]
+
+
+def test_empty_text_ref_is_stamped_final_and_counts_toward_completion():
+    """No text is a finished state, not a failure: stamp it so the next
+    run fingerprint-skips it, and let the docket still seal complete."""
     blank = DocRef(
         key="K9", collection="comments", docket="D", fingerprint="x", load=lambda: None
     )
-    stats, _, conn, _ = _run(
-        [_ref("fp1"), blank], [], sealed={"D": "2026-10-20T00:00:00Z"}
+    stats, store, conn, _ = _run([blank], [], sealed={"D": "s"})
+    assert stats["skipped"] == 1 and stats["indexed"] == 0
+    store.add_embeddings.assert_not_called()
+    ins = _state_inserts(conn)
+    assert len(ins) == 1
+    assert ins[0].args[1] == {"k": "K9", "c": "comments", "h": "", "n": 0, "f": "x"}
+    assert stats["docket_complete"] == 1
+    assert _docket_inserts(conn)
+
+
+def test_stamped_empty_row_is_fingerprint_skipped_on_the_next_run():
+    loads = []
+    blank = DocRef(
+        key="K9",
+        collection="comments",
+        docket="D",
+        fingerprint="x",
+        load=lambda: loads.append("K9"),
     )
-    assert stats["skipped"] == 1 and stats["indexed"] == 1
-    assert stats["docket_complete"] == 0
-    assert not [
-        c
-        for c in conn.execute.call_args_list
-        if "INSERT INTO index_docket_state" in str(c.args[0])
-    ]
+    stats, _, conn, _ = _run([blank], [("K9", "", "x")])
+    assert stats["fingerprint_skipped"] == 1 and stats["skipped"] == 0
+    assert loads == []  # stamped-empty rows are never re-loaded
+    assert _state_inserts(conn) == []
 
 
 def test_sealed_docket_not_marked_when_a_ref_yields_no_chunks():
+    """Text that chunks to nothing is a real failure — it blocks the seal
+    and is not stamped."""
     stats, _, conn, _ = _run(
-        [_ref("fp1")], [], sealed={"D": "s"}, chunks_for=lambda d, c: []
+        [_ref("fp1")], [], sealed={"D": "s"}, chunk_doc=lambda d: []
     )
     assert stats["skipped"] == 1 and stats["docket_complete"] == 0
-    assert not [
-        c
-        for c in conn.execute.call_args_list
-        if "INSERT INTO index_docket_state" in str(c.args[0])
-    ]
+    assert _state_inserts(conn) == []
+    assert _docket_inserts(conn) == []