fix: restore the GuideEntry dataclass, repairing the i2v guide stack

7106db0 added scene_anchor_media_refs by writing it over the "@dataclass /
class GuideEntry:" header lines. The class body survived as unreachable code
after that function's return, so GuideEntry was referenced in three places but
never defined.

Effect: every code path that switches the per-scene i2v guide stack on raised
NameError -- build_scene_guides_payload and continuity_media_refs both died as
soon as guide_settings.stack_enabled was true. It went unnoticed for seven
weeks because the stack defaults off and no test covered it.

Fix moves the stranded body back out of scene_anchor_media_refs and restores
the two lost header lines. The body is byte-identical to b9f6e74; only its
position and header changed. scene_anchor_media_refs is untouched.

Adds two regression tests, both verified to fail against the unfixed file.
Tests: 22 failed / 462 passed (baseline 22/460 -- +2 passing, 0 new failures).

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

movie_editor/backend/timeline.py

@@ -234,20 +234,8 @@ def continuity_media_refs(full: Project, target: Project) -> list[str]:
     return list(dict.fromkeys(refs))
 
 
-def scene_anchor_media_refs(target: Project) -> list[str]:
-    """Media-bin ids required as i2v anchors on generative scenes."""
-    refs: list[str] = []
-    for sc in target.scenes:
-        if sc.excluded or is_video_clip(sc):
-            continue
-        src = sc.source
-        if not src:
-            continue
-        stype = source_type(sc)
-        ref = src.media_ref
-        if ref and stype in ("image", "generated_frame", "mixed", "anchor_guide"):
-            refs.append(ref)
-    return list(dict.fromkeys(refs))
+@dataclass
+class GuideEntry:
     """Optional per-scene guide (only used when project guide_settings.stack_enabled)."""
     enabled: bool = True
     source: str = "template"   # "template" | "scene" | "image"
@@ -274,6 +262,22 @@ def scene_anchor_media_refs(target: Project) -> list[str]:
         return asdict(self)
 
 
+def scene_anchor_media_refs(target: Project) -> list[str]:
+    """Media-bin ids required as i2v anchors on generative scenes."""
+    refs: list[str] = []
+    for sc in target.scenes:
+        if sc.excluded or is_video_clip(sc):
+            continue
+        src = sc.source
+        if not src:
+            continue
+        stype = source_type(sc)
+        ref = src.media_ref
+        if ref and stype in ("image", "generated_frame", "mixed", "anchor_guide"):
+            refs.append(ref)
+    return list(dict.fromkeys(refs))
+
+
 def is_mixed_source(scene: Scene) -> bool:
     return (scene.source.type or "carry") == "mixed"
 

movie_editor/tests/test_timeline.py

@@ -239,6 +239,34 @@ def test_guide_settings_default_off():
     assert gs["accumulate_prior"] is False
 
 
+def test_guide_entry_is_importable_and_round_trips():
+    """GuideEntry's class header was once overwritten by a neighbouring function,
+    leaving its body stranded as dead code after a `return`. Nothing caught it because
+    the guide stack defaults off, so no other test reaches the code that uses it."""
+    from movie_editor.backend.timeline import GuideEntry
+
+    g = GuideEntry.from_dict({"enabled": True, "source": "image", "media_ref": "img1"})
+    assert g.enabled is True and g.source == "image" and g.media_ref == "img1"
+    assert g.to_dict()["strength"] == 0.35
+
+
+def test_guide_stack_enabled_paths_do_not_raise():
+    """Both consumers of GuideEntry only run when the stack is switched on — the exact
+    configuration that used to raise NameError."""
+    p = _project(
+        guide_settings={"stack_enabled": True},
+        scenes=[
+            {"id": "s1", "text": "a", "source": {"type": "image", "media_ref": "img1"}},
+            {"id": "s2", "text": "b", "source": {"type": "mixed", "media_ref": "img2"},
+             "guides": [{"enabled": True, "source": "image", "media_ref": "img3"}]},
+        ],
+    )
+    payload = build_scene_guides_payload(p)
+    assert payload["stack_enabled"] is True
+    assert payload["scenes"][1][0]["media_ref"] == "img3"
+    assert "img3" in continuity_media_refs(p, p)
+
+
 def test_continuity_defaults_auto_on():
     cs = normalize_continuity_settings({})
     assert cs["auto_enabled"] is True