Counters: a total padded wider than its index is none; report diff on shared ranges

- "Very Best Of The Who [01/010]", "[02/020]", "[07/070]": a posting tool's
  total of index×10, so every track had a total of its own and was a
  release of its own. A total zero-padded wider than its index is no
  counter ("[001/010]" still is).
- corpus_sweep.py report compares builds over the ranges both replayed (the
  corpus grows between builds).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

deploy/corpus_sweep.py

@@ -113,13 +113,20 @@ def replay():
         shutil.rmtree(os.path.join(OUT, b))
 
 
-def load(build):
-    """Releases of one build's replay, merged by (group, key) as the catalog does."""
+def replayed(build):
+    """The ranges a build replayed, as paths relative to its directory."""
+    root = os.path.join(OUT, build)
+    return {os.path.relpath(os.path.join(d, f), root) for d, _, files in os.walk(root) for f in files if f.endswith('.jsonl')}
+
+
+def load(build, only=None):
+    """Releases of one build's replay (of the ranges in `only`, when given), merged by (group, key) as the catalog does."""
     releases = {}
-    for dirpath, _, files in os.walk(os.path.join(OUT, build)):
-        for f in files:
-            if not f.endswith('.jsonl'):
-                continue
+    for rel in sorted(replayed(build)):
+        if only is not None and rel not in only:
+            continue
+        dirpath, f = os.path.split(os.path.join(OUT, build, rel))
+        if True:
             for line in open(os.path.join(dirpath, f), encoding='utf-8', errors='replace'):
                 r = json.loads(line)
                 k = (r['group'], r['key'])
@@ -182,10 +189,12 @@ def report():
         show(r, '  ')
 
     if len(builds) >= 2:
-        before = load(builds[-2][1])
-        print(f'\n== change since build {builds[-2][1]}: {len(before):,} → {len(rel):,} releases')
+        # Over the ranges both replayed: the corpus grows between builds.
+        both = replayed(builds[-2][1]) & replayed(build)
+        before, after = load(builds[-2][1], both), load(build, both)
+        print(f'\n== change since build {builds[-2][1]} on the {len(both)} ranges both replayed: {len(before):,} → {len(after):,} releases')
         names = lambda rs: collections.Counter((r['group'], r['name']) for r in rs.values())
-        a, b = names(before), names(rel)
+        a, b = names(before), names(after)
         moved = sorted(set(a) | set(b), key=lambda k: -abs(a[k] - b[k]))[:20]
         for k in moved:
             if a[k] != b[k]: