hero reel: remove walking shot, shorten opener

Drop v3-shot-03 (feet walking on carpet) from reel and trim v3-shot-02
opener from 4.5s to 3.0s. Bump cachebuster to v=7.

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

tools/build-paced-reel.py

@@ -18,7 +18,6 @@ os.makedirs(TMP_DIR, exist_ok=True)
 CLIPS = [
     "v3-shot-02",              # 1  - wine spill on sofa
     "shot-05-extraction-couch",# 2  - extraction couch
-    "v3-shot-03",              # 3  - dirty stained carpet close-up
     "v3-shot-06",              # 4  - living room clean carpet pan
     "v3-shot-07",              # 5  - restaurant carpet glide
     "v3-shot-05",              # 6  - office lobby carpet pan
@@ -32,10 +31,9 @@ CLIPS = [
 
 # Duration for each clip
 DURATIONS = [
-    4.5,   # 1  wine spill — cut at 4.5s
+    3.0,   # 1  wine spill — shortened to 3.0s
     5.0,   # 2
-    4.0,   # 3  --- building pace ---
-    4.0,   # 4
+    4.0,   # 4  --- building pace ---
     4.0,   # 5
     3.5,   # 6
     3.5,   # 7