volt: land Q137's open-set artifact (untracked), fix its stale digest, add the 11th gate leg

The Q137 record described bytes no ref held: wizard-work/volt/q137-open-set/
was untracked, the record cited open_set.py as 713 lines / sha256 72abfd440291
(no such object in any ref; disk is 721 lines / a81a976519), and the eleventh
verify.py leg was uncommitted. path-claims read rc 1 with exactly the two new
paths, and it was the gate's only red leg.

Landing: open_set.py, CHECK-q137, REPORT.md, the queue addendum, the
re-rendered index, tools/verify.py's open-set leg.

After: CHECK-q137 4/4 rc 0; verify.py --selftest 59/59; verify.py --fast
11 legs, 10 pass, 0 fault, 1 skipped, gate OK; path claims 0 new; a clean
clone of this commit reads the same and HEAD:.../open_set.py sha256 equals
the digest the addendum states.

tools/verify.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-"""verify.py -- the HOME the index gate did not have: one command, ten legs,
+"""verify.py -- the HOME the index gate did not have: one command, eleven legs,
 one exit code, and a row per leg so a partial run cannot look like a clean one.
 
 WHY THIS EXISTS
@@ -96,6 +96,13 @@ WHAT IT RUNS -- one row per leg, cheapest first, never in parallel
                   files; the leg is here because a guard nothing runs is not a
                   guard -- `afb231d` reverted all ten blobs and no gate leg saw
                   the three artifacts.
+  open-set        wizard-work/volt/q137-open-set/open_set.py --check
+                  the queue's declared open set, derived from its own records
+                  and graded against a pin: 0 open, 26 ids ever opened, 97
+                  headings / 97 records. A record appended without re-pinning
+                  moves the count and reds this leg. The closure probes
+                  (--closures) are NOT in the leg -- they read other lanes'
+                  modules and cost ~3 s; `bash CHECK-q137` runs all four.
 
   The legs are ordered by cost, and a leg is never skipped because an earlier
   one failed: a stale index and a broken selftest are different defects and the
@@ -223,6 +230,10 @@ LEGS = (
      "what": "every repair a closed item landed is still the bytes that landed "
              "(sha256 pins for Q109/Q120 and the seven Q126 cells) and its "
              "cell still runs green"},
+    {"key": "open-set", "tool": "open_set.py", "slow": False,
+     "path": os.path.join("wizard-work", "volt", "q137-open-set", "open_set.py"),
+     "what": "the work queue's declared open set and its record counts, "
+             "graded against a pin (Q137: 0 open, 26 ever opened)"},
 )
 
 # A detail line is a courtesy, not the verdict -- but a verdict with no line
@@ -435,6 +446,13 @@ def leg_argv(key, repo, queue, index, checkin_day=None):
                 os.path.join(repo, "wizard-work", "spark",
                              "closed_artifact_guard.py"),
                 "--root", repo]
+    if key == "open-set":
+        # --repo, so the queue graded is the one in the tree under test and not
+        # the copy beside this tool; --check reads and compares, nothing more.
+        return [sys.executable,
+                os.path.join(repo, "wizard-work", "volt", "q137-open-set",
+                             "open_set.py"),
+                "--repo", repo, "--check"]
     raise KeyError(key)
 
 
@@ -700,7 +718,9 @@ GREEN_ALL = {"checkin_check.py": 0, "path_claim_check.py": 0,
              "selftest_sweep.py": 0, "write_probe.py": 0,
              "import_resolve_check.py": 0,
              os.path.join("wizard-work", "spark",
-                          "closed_artifact_guard.py"): 0}
+                          "closed_artifact_guard.py"): 0,
+             os.path.join("wizard-work", "volt", "q137-open-set",
+                          "open_set.py"): 0}
 
 
 def selftest():
@@ -720,8 +740,8 @@ def selftest():
         # 1. ten green stubs -> rc 0
         repo = _fixture(os.path.join(td, "c1"), GREEN_ALL)
         rc, out = _verify("--repo", repo)
-        check("1 all ten legs green -> rc 0", rc, 0)
-        check("1b summary counts the ten legs", "verify: 10 legs, 10 pass, 0 fault, "
+        check("1 all eleven legs green -> rc 0", rc, 0)
+        check("1b summary counts the eleven legs", "verify: 11 legs, 11 pass, 0 fault, "
               "0 ungradable, 0 skipped" in out, True)
 
         # 2. a stale index is a FAULT, and its own line reaches the row
@@ -778,7 +798,7 @@ def selftest():
         check("7 --json writes the rows", [r["key"] for r in obj.get("rows", [])],
               ["checkin", "path-claims", "reply-headings", "index-current",
                "append-audit", "doc-commands", "selftest-sweep", "write-axis",
-               "import-resolve", "closed-artifacts"])
+               "import-resolve", "closed-artifacts", "open-set"])
         check("7b --json carries the same rc the process returned",
               obj.get("rc"), rc)
 
@@ -822,7 +842,7 @@ def selftest():
         check("12 skipped leg is its own count in --json",
               obj.get("counts", {}).get("SKIP"), 1)
         check("12b and the skipped leg is not counted as a pass",
-              obj.get("counts", {}).get(PASS), 9)
+              obj.get("counts", {}).get(PASS), 10)
 
         # 13. the detail line must not contradict the verdict: a row graded
         # FAULT beside "0 fatal" is the SILENT failure this gate exists to catch.