Adding fixes to video build

gnommo/transformer.py

@@ -639,6 +639,7 @@ def build_render_plan(
     slide_range: Optional[tuple[str, Optional[str]]] = None,
     narration_schedule: Optional[list] = None,
     narration_source: Optional[VideoSource] = None,
+    marker_timings_override: Optional[list["MarkerTiming"]] = None,
 ) -> tuple[RenderPlan, list[MarkerTiming]]:
     """
     Build a complete render plan from manuscript and transcription.
@@ -650,6 +651,12 @@ def build_render_plan(
         manuscript_text: The manuscript.txt content (source of truth for markers)
         transcription: Word-level timestamps from whisper transcription
         slide_range: Optional tuple of (start_slide, end_slide) for partial rendering.
+        marker_timings_override: When provided (e.g. loaded from events.json /
+            scaffold.json), these timings are used verbatim instead of aligning
+            against the transcript. Their timestamps are already final-timeline
+            values, so the narration-skip adjustment below is skipped for them.
+            This is the seam that lets `render` consume a hand-edited scaffold
+            without re-running (and re-breaking on) fuzzy alignment.
 
     Returns:
         Tuple of (RenderPlan, list of MarkerTiming for display)
@@ -657,10 +664,14 @@ def build_render_plan(
     audio = audio or {}
     audio_dir = audio_dir or project_path
 
-    # Align markers to transcription timestamps
-    marker_timings = align_markers_to_transcription(
-        manuscript_text, transcription, slides=slides, videos=videos, audio=audio
-    )
+    # Align markers to transcription timestamps — unless caller supplied timings
+    # (from the scaffold/events layer), in which case those win verbatim.
+    if marker_timings_override is not None:
+        marker_timings = marker_timings_override
+    else:
+        marker_timings = align_markers_to_transcription(
+            manuscript_text, transcription, slides=slides, videos=videos, audio=audio
+        )
 
     # Find shared_assets directory
     shared_assets_dir = None
@@ -702,8 +713,9 @@ def build_render_plan(
         full_duration = get_video_duration(video_path)
 
     # Apply skip offset: if narration starts at `skip` seconds, subtract it from
-    # all marker timestamps so they line up with the trimmed timeline.
-    if narration_skip > 0:
+    # all marker timestamps so they line up with the trimmed timeline. Skipped for
+    # override timings, which are already expressed in the final timeline.
+    if narration_skip > 0 and marker_timings_override is None:
         for timing in marker_timings:
             if timing.timestamp >= 0:
                 timing.timestamp = max(0.0, timing.timestamp - narration_skip)