test: end-to-end user journey in CI; fix ALS vectors for small libraries

- newApp (extracted from main) is the exact production wiring; the
  `ci / db` job now also runs it on PostgreSQL, Redis and Meilisearch
  and walks the main user flows over HTTP: first admin sign-in and
  credential change, local source and scan, search, album / artist /
  top tracks, signed stream, events and history, likes, fallback wave,
  playback state, upload queue up to review.
- ALS on a small library produced fewer than 64 factors and the insert
  into vector(64) failed; vectors are now zero-padded to the column size.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

services/recommender/tests/test_train.py

@@ -108,3 +108,11 @@ def test_engine_uses_cf_source() -> None:
     assert len(picks) == 5
     assert sum(int(p.id[1:]) < 20 for p in picks) >= 4  # почти всё — из «своей» половины по ALS
     assert model_version(index, profile).endswith("+cf")
+
+
+def test_cf_vectors_are_padded_to_column_size() -> None:
+    from pipu_rec.train.pipeline import CF_DIM, pad
+
+    v = np.ones((3, 5), dtype=np.float32)
+    assert pad(v).shape == (3, CF_DIM)
+    assert pad(np.ones((2, 80), dtype=np.float32)).shape == (2, CF_DIM)