v3 library: song Details drawer + bulk edit — P2 (#703)

* v3 library: song Details drawer + bulk edit — P2

Evolves the per-song editing surface from the legacy modal into a v3
slide-in Details drawer (the filter-drawer idiom, body-appended): catalog
fields (title/artist/album/year, written through the existing atomic
manifest writer) plus the P1 personal layer - your difficulty (1-5),
tags, and notes - with the heart staying the existing favorite system.

- Cards badge the personal layer at rest (difficulty pip + tag count,
  top-right, fading on hover so the action buttons keep that corner);
  un-annotated cards render byte-identical to before.
- Bulk edit from the select-mode batch bar: POST
  /api/songs/user-meta/batch applies additive tag add/remove and a
  leave/set/clear difficulty across the selection (mixed-state aware).
- The core card action relabels to "Details" and opens the drawer via a
  feature-detected global, falling back to the legacy modal when the
  drawer isn't mounted.

16 batch tests new; the P1 user-meta suite stays green.
tailwind.min.css rebuilt for the drawer's utility classes.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Nm7tHs1Yvjjtnnu4nzJgdN

* fix(v3): surface bulk-edit / save-details request failures instead of reporting success (PR #703 review)

Check the batch/write responses and show an fbNotify error (keeping selection and drawer) instead of unconditionally closing as success.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Co-authored-by: byrongamatos <xasiklas@gmail.com>

tests/test_batch_user_meta.py

@@ -0,0 +1,152 @@
+"""Tests for the bulk personal-meta endpoint (P2):
+POST /api/songs/user-meta/batch — the apply-to-all behind the Songs batch bar.
+DB-only, never touches files. Additive by design: bulk tag edits ADD/REMOVE
+(never full-replace) and an omitted `set_difficulty` leaves each song's own
+value alone (mixed-state "leave unchanged")."""
+
+import importlib
+import sys
+
+import pytest
+from fastapi.testclient import TestClient
+
+
+@pytest.fixture()
+def server(tmp_path, monkeypatch, isolate_logging):
+    monkeypatch.setenv("CONFIG_DIR", str(tmp_path))
+    monkeypatch.setenv("FEEDBACK_SKIP_STARTUP_TASKS", "1")
+    sys.modules.pop("server", None)
+    srv = importlib.import_module("server")
+    try:
+        yield srv
+    finally:
+        conn = getattr(getattr(srv, "meta_db", None), "conn", None)
+        if conn is not None:
+            conn.close()
+        sys.modules.pop("server", None)
+
+
+@pytest.fixture()
+def client(server):
+    return TestClient(server.app)
+
+
+def _seed(server, *filenames):
+    for fn in filenames:
+        server.meta_db.put(fn, 0, 0, {"title": fn.split(".")[0], "artist": "A"})
+
+
+def _um(client, fn):
+    return client.get(f"/api/song/{fn}/user-meta").json()
+
+
+BATCH = "/api/songs/user-meta/batch"
+
+
+# ── Difficulty across a selection ────────────────────────────────────────────
+
+def test_batch_set_difficulty_on_all(client, server):
+    _seed(server, "a.archive", "b.archive", "c.archive")
+    r = client.post(BATCH, json={"filenames": ["a.archive", "b.archive"],
+                                 "set_difficulty": 4})
+    assert r.status_code == 200
+    assert r.json()["updated"] == 2
+    assert _um(client, "a.archive")["user_difficulty"] == 4
+    assert _um(client, "b.archive")["user_difficulty"] == 4
+    # untouched song stays unset
+    assert _um(client, "c.archive")["user_difficulty"] is None
+
+
+def test_batch_clear_difficulty_preserves_notes(client, server):
+    _seed(server, "a.archive", "b.archive")
+    client.put("/api/song/a.archive/user-meta", json={"user_difficulty": 3, "notes": "keep me"})
+    client.put("/api/song/b.archive/user-meta", json={"user_difficulty": 2})
+    r = client.post(BATCH, json={"filenames": ["a.archive", "b.archive"],
+                                 "set_difficulty": None})
+    assert r.status_code == 200
+    # a still has its notes; b (no notes) is fully cleared
+    a = _um(client, "a.archive")
+    assert a["user_difficulty"] is None and a["notes"] == "keep me"
+    assert _um(client, "b.archive") == {"user_difficulty": None, "notes": "", "tags": []}
+
+
+def test_omitting_set_difficulty_leaves_each_value(client, server):
+    """Mixed-state: no set_difficulty key → every song keeps its own difficulty
+    while tags still apply."""
+    _seed(server, "a.archive", "b.archive")
+    client.put("/api/song/a.archive/user-meta", json={"user_difficulty": 1})
+    client.put("/api/song/b.archive/user-meta", json={"user_difficulty": 5})
+    client.post(BATCH, json={"filenames": ["a.archive", "b.archive"],
+                             "add_tags": ["gig"]})
+    assert _um(client, "a.archive")["user_difficulty"] == 1
+    assert _um(client, "b.archive")["user_difficulty"] == 5
+    assert _um(client, "a.archive")["tags"] == ["gig"]
+
+
+# ── Tags: additive, never full-replace ───────────────────────────────────────
+
+def test_batch_add_tags_does_not_clobber_existing(client, server):
+    _seed(server, "a.archive", "b.archive")
+    client.put("/api/song/a.archive/user-meta", json={"tags": ["existing"]})
+    client.post(BATCH, json={"filenames": ["a.archive", "b.archive"],
+                             "add_tags": ["Warm-ups", "warm-ups"]})  # dupe-folds
+    assert _um(client, "a.archive")["tags"] == ["existing", "warm-ups"]
+    assert _um(client, "b.archive")["tags"] == ["warm-ups"]
+
+
+def test_batch_remove_tags(client, server):
+    _seed(server, "a.archive", "b.archive")
+    client.put("/api/song/a.archive/user-meta", json={"tags": ["gig", "riffs"]})
+    client.put("/api/song/b.archive/user-meta", json={"tags": ["gig"]})
+    client.post(BATCH, json={"filenames": ["a.archive", "b.archive"],
+                             "remove_tags": ["gig"]})
+    assert _um(client, "a.archive")["tags"] == ["riffs"]
+    assert _um(client, "b.archive")["tags"] == []
+
+
+def test_add_wins_over_remove_conflict(client, server):
+    _seed(server, "a.archive")
+    client.post(BATCH, json={"filenames": ["a.archive"],
+                             "add_tags": ["keep"], "remove_tags": ["keep"]})
+    assert _um(client, "a.archive")["tags"] == ["keep"]
+
+
+def test_returned_tag_vocabulary_refreshes(client, server):
+    _seed(server, "a.archive", "b.archive")
+    body = client.post(BATCH, json={"filenames": ["a.archive", "b.archive"],
+                                    "add_tags": ["warmups"]}).json()
+    assert {"tag": "warmups", "count": 2} in body["tags"]
+
+
+# ── Validation ───────────────────────────────────────────────────────────────
+
+def test_empty_filenames_is_400(client, server):
+    assert client.post(BATCH, json={"filenames": [], "set_difficulty": 3}).status_code == 400
+    assert client.post(BATCH, json={"set_difficulty": 3}).status_code == 400
+
+
+def test_nothing_to_apply_is_400(client, server):
+    _seed(server, "a.archive")
+    assert client.post(BATCH, json={"filenames": ["a.archive"]}).status_code == 400
+
+
+@pytest.mark.parametrize("bad", [0, 6, 2.5, "x", True])
+def test_bad_set_difficulty_is_400(client, server, bad):
+    _seed(server, "a.archive")
+    assert client.post(BATCH, json={"filenames": ["a.archive"],
+                                    "set_difficulty": bad}).status_code == 400
+
+
+def test_tags_must_be_arrays(client, server):
+    _seed(server, "a.archive")
+    assert client.post(BATCH, json={"filenames": ["a.archive"],
+                                    "add_tags": "gig"}).status_code == 400
+
+
+def test_batch_survives_rescan(client, server):
+    _seed(server, "a.archive")
+    client.post(BATCH, json={"filenames": ["a.archive"],
+                             "set_difficulty": 3, "add_tags": ["t"]})
+    server.meta_db.put("a.archive", 1, 1, {"title": "a", "artist": "A"})
+    m = _um(client, "a.archive")
+    assert m["user_difficulty"] == 3 and m["tags"] == ["t"]