fix(u6): fold the cold code-review panel — four-arm convergence on three surface clauses

/heid-code-review panel 01M35CK8YKEKMV7T15JXEF6A8N, verdict NOT drift-zero.
Three findings arrived from all four arms independently, and they share a
shape: a contract clause written as prose and never converted into an
assertion. That is the lens working.

- The panel dropped the added date the contract promised to show.
- `bench ls` printed no ids, and the URL it printed was truncated to 52 columns
  so the line was not pasteable into `bench state|rm`. The test's docstring
  claimed it printed ids and asserted nothing of the kind.
- `bench import` printed the description instead of the raw URL beside each
  normalized id, hiding the collapse the clause exists to expose.
- An IPv6 literal lost its brackets: http://[::1]:8080/a normalized to
  http://::1:8080/a, a broken identity that no re-post can match. Bracketed
  literals are re-wrapped; an unbracketed one is refused rather than guessed.
- A deeply-nested JSON RecursionError escaped read_benches' except pair. The
  byte cap does not help -- 200k open brackets is 200 KB.
- An empty board hid the whole benches panel, registration form included.
- The link refusal classified by captured-text emptiness, which bash can erase;
  it now answers with a B:/N sentinel so no name reads as "not a booth".

INV-4's tie-break falsifier could not fail: _write_all serializes with
sort_keys=True, so both insertion orders came back already id-sorted and
removing the tie-break left the test green. It now calls order_benches
directly. Same class as the five vacuous U4 falsifiers, found by a cold reader
rather than by us.

Also from the arms' per-invariant vacuity pass: INV-6 had no vector pinning a
non-default port as part of the identity; INV-3 asserted only that links/ was
absent; INV-8's hashed sequence omitted a read verb; INV-9's AST walk is
defeated by a string import. All closed.

Contract amended where the code was right: `updated` means last mutation, the
id cap is write-only because the id is the locator controls post back, INV-8's
file list includes the lock sidecar it always mandated. Every line number is
out of the prose -- the panel found two already stale.

565 -> 593 tests. Nothing declined.

tests/test_cli.py

@@ -358,6 +358,7 @@ REFUSED = 2
 # decides what a booth URL is, and these are the rows the CLI must agree on.
 # A second `/b/` check inlined in the shell for speed goes red HERE.
 from test_benches import BOOTH_URL_TABLE  # noqa: E402
+from booth.benches import normalize_bench_url as normalize_bench_url_cli  # noqa: E402
 
 
 @pytest.mark.parametrize("url,is_booth", [(u, e is not None) for u, e in BOOTH_URL_TABLE])
@@ -378,9 +379,14 @@ def test_a_refused_link_writes_nothing_at_all(booth):
     data, _ = booth
     board = data / "links"
     assert not board.exists()
+    before = sorted(p.name for p in data.iterdir())
     r = run(data, "link", "http://10.100.10.50:8090/b/some-booth/", "nope")
     assert r.returncode == REFUSED
-    assert not board.exists(), f"a refused link left {sorted(p.name for p in board.iterdir())}"
+    assert not board.exists(), "a refused link created the board directory"
+    # NOTHING AT ALL, not just no board. Asserting only `links/`'s absence let
+    # a refusal that touched `.benches.lock` (or any other sidecar) on its way
+    # out stay green — the cold panel's vacuity pass named exactly that.
+    assert sorted(p.name for p in data.iterdir()) == before, "a refused link wrote something"
 
 
 def test_the_refusal_names_the_alternative(booth):
@@ -410,6 +416,18 @@ def test_bench_add_is_an_upsert(booth):
     r = run(data, "bench", "ls")
     assert r.returncode == OK, r.stderr
     assert r.stdout.count("talk v") == 1 and "talk v2" in r.stdout
+    # THE ID, WHOLE AND UNTRUNCATED, because it is the locator `bench state`
+    # and `bench rm` take. An earlier version of this test had a docstring
+    # claiming `bench ls` prints ids and asserted nothing of the kind, while
+    # the code printed a url truncated to 52 columns — a claim standing in for
+    # evidence, which is how the drift would have survived CI. Found by all
+    # four cold arms independently.
+    bid = normalize_bench_url_cli("https://talk.nh3.phasefinal.com:8092/")
+    assert bid in r.stdout, r.stdout
+    # and what ls prints is addressable, end to end
+    line = [l for l in r.stdout.splitlines() if "talk v2" in l][0]
+    printed_id = line.split()[-1]
+    assert run(data, "bench", "state", printed_id, "promoted").returncode == OK
 
 
 def test_bench_verbs_round_trip(booth):
@@ -476,6 +494,12 @@ def test_import_classifies_into_three_groups(booth):
     assert "gone" in out          # the booth row, skipped
     assert "talk" in out          # a candidate
     assert "ftp://x.test/f" in out  # refused, with its reason
+    # THE RAW URL BESIDE THE NORMALIZED ID, which is the entire point of the
+    # proposal: five rows of `talk` collapsing to one is only checkable if you
+    # can see which raw URLs produced the one id. This printed the description
+    # instead, so the collapse was invisible in the one place it had to be
+    # visible. All four cold arms found it.
+    assert out.count("https://talk.nh3.phasefinal.com:8092/") >= 2, out
 
 
 def test_import_apply_collapses_the_repost(booth):
@@ -503,6 +527,7 @@ def test_nothing_in_the_unit_touches_links_md(booth):
     run(data, "bench", "import", "--apply")
     run(data, "bench", "add", "http://new.test/", "new")
     run(data, "bench", "state", "http://new.test/", "retired")
+    run(data, "bench", "ls")          # a read verb can truncate too
     run(data, "bench", "rm", "http://new.test/")
     after = hashlib.sha256((board / "links.md").read_bytes()).hexdigest()
     assert before == after