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>

spec/tests/test-import-bind.sx

@@ -1,3 +1,5 @@
+(defsuite "import-bind"
+
 ;; Tests for define-library, import, and the import suspension mechanism
 
 ;; ============================================================
@@ -190,3 +192,5 @@
   (assert=
     (cek-try (fn () inner-secret) (fn (e) "not-found"))
     "not-found"))
+
+)