feat(annotate): Module 1 samples image frames at fps rate

Replace the fixed max_video_frames count with a rate (default 1 fps).
A 30 s episode now sends 30 frames; a 5 s episode sends 5; capped at
max_video_frames (default 128) to avoid blowing up the payload on long
episodes.

Override with --module_1.frames_per_second=2.0 for denser sampling, or
--module_1.frames_per_second=0.5 for sparser.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/lerobot/annotations/steerable_pipeline/config.py

@@ -32,7 +32,14 @@ class Module1Config:
     """
 
     enabled: bool = True
-    max_video_frames: int = 32
+    frames_per_second: float = 1.0
+    """Sample one image-frame per ``1/fps`` seconds across the episode for
+    Module 1's subtask-decomposition prompt. ``1.0`` = 1 fps. Capped by
+    ``max_video_frames`` to avoid blowing up the request payload."""
+    max_video_frames: int = 128
+    """Hard cap on the number of frames Module 1 sends. With ``fps=1`` and
+    a 30 s episode this yields 30 frames. Bumped from 32 since each frame
+    is small (~30-100 KB PNG when base64'd)."""
     min_subtask_seconds: float = 1.5
     plan_max_steps: int = 8
     use_video_url: bool = False

src/lerobot/annotations/steerable_pipeline/modules/plan_subtasks_memory.py

@@ -175,9 +175,12 @@ class PlanSubtasksMemoryModule:
                 else []
             )
         else:
-            video_frames = self.frame_provider.video_for_episode(
+            target_count = max(
-                record, self.config.max_video_frames
+                1,
+                int(round(episode_duration * self.config.frames_per_second)),
             )
+            target_count = min(target_count, self.config.max_video_frames)
+            video_frames = self.frame_provider.video_for_episode(record, target_count)
             video_block = to_video_block(video_frames)
         content = [*video_block, {"type": "text", "text": prompt}]
         messages = [{"role": "user", "content": content}]