Fix row-count mismatch in extract_episode for PhAIL signals

robot_state.q and robot_commands.pose have different sampling rates,
producing arrays with incompatible row counts. Truncate both to
min(rows) before computing tracking effort.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app.py

@@ -42,9 +42,11 @@ def extract_episode(states, actions):
     actions = np.array(actions, dtype=float)
     dq      = np.diff(states, axis=0)
     speed   = np.linalg.norm(dq, axis=1) * FS
-    # align dims before subtracting — state and action may differ (e.g. Franka 13 vs 15)
-    min_dim = min(states.shape[1], actions.shape[1])
-    effort  = np.linalg.norm(actions[:, :min_dim] - states[:, :min_dim], axis=1)
+    # align both rows and dims before subtracting
+    min_rows = min(len(states), len(actions))
+    min_dim  = min(states.shape[1], actions.shape[1])
+    effort   = np.linalg.norm(
+        actions[:min_rows, :min_dim] - states[:min_rows, :min_dim], axis=1)
     raw_z   = states[:, 1]
     z       = (raw_z - raw_z.min()) / (raw_z.max() - raw_z.min() + 1e-9)
     return speed, effort, z