W14: C9 eliminate empty suite labels (test-only) — section E complete

The finding ("spec suites print with empty suite label") was six files
wide: test-chars (43 suite-less top-level deftests), test-import-bind
(14), test-ports (12), test-let-match (8), test-math (deftests NESTED in
deftests — every test reported as " > sin"), and 4 stray deftests between
suites in test-hyperscript-conformance.

Fixes: file-level defsuite wraps for the four flat files (mechanical wrap,
sx_validate-checked); test-math restructured deftest->defsuite ("math >
string->number"); hs strays wrapped in suites named for their section
comments (hs-compat-blockLiteral/cookies/some/where). The two
baseline-visible identities are renamed in spec/tests/known-failures.txt
in this same commit — the F10 gate enforces exactly this coupling.

Full baseline gate validated GREEN: 5798p/273f, fail set identical
(the -2 passes are the two wrapper deftests that no longer self-report
a vacuous PASS around their children).

Test-only: no semantics edits, no push.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

plans/agent-briefings/sx-gate-loop.md

@@ -98,13 +98,28 @@ Pin each confirmed-and-fixed finding with a minimal repro. Add suites to
       (`scripts/test-suite-baseline.sh` + `spec/tests/known-failures.txt`,
       273 pinned: 271 hs-* + 2 empty-suite-label entries → C9 evidence).
       New failure OR vanished failure = red; hs loops' scoreboards untouched
-- [ ] C9 — empty suite label
+- [x] C9 — empty suite labels ELIMINATED: 6 files had suite-less top-level
+      deftests (chars 43, import-bind 14, ports 12, let-match 8, math
+      nested-deftests, 4 hs strays) — wrapped/restructured into defsuites;
+      baseline identities updated in the same commit
 
 ### F. Differential battery
 - [ ] F8 — cross-host differential battery (same source, all hosts agree)
 
 ## Progress log (newest first)
 
+- 2026-07-04 — **C9 empty-suite labels (item E.3) — section E COMPLETE**.
+  The sweep found the defect much wider than the finding: SIX files carried
+  suite-less top-level deftests (test-chars 43, test-import-bind 14,
+  test-ports 12, test-let-match 8, test-math as deftest-nested-in-deftest,
+  test-hyperscript-conformance 4 strays between suites). Fixes: file-level
+  defsuite wraps (validated via sx_validate after mechanical wrap),
+  test-math restructured deftest→defsuite (labels now "math > sin"),
+  hs strays wrapped in section-comment-named suites (hs-compat-
+  blockLiteral/cookies/some/where). The two baseline-visible identities
+  renamed in known-failures.txt in the SAME commit. Full-gate validated
+  GREEN (5798p/273f — −2 passes are the wrapper deftests that no longer
+  self-report; fail set byte-identical). Test-only.
 - 2026-07-04 — **F10 baseline gate (item E.2)**. Deliberately NOT a
   skip-list: skip-listing the hs red band in the runner would rewrite the
   hs loops' scoreboards mid-flight. Instead