cl: Phase 5 macros+LOOP + Phase 2 dynamic vars — 464/464 tests

defmacro/macrolet/symbol-macrolet/macroexpand, gensym/gentemp, full
LOOP macro (loop.sx) with all clause types. Phase 2 dynamic variables:
cl-apply-dyn, cl-letstar-bind, cl-mark-special!/cl-special? for
defvar/defparameter specials with let-based dynamic rebinding.
27 macro+LOOP tests; 182 eval tests (8 new dynamic var tests).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/common-lisp/scoreboard.json

@@ -1,6 +1,6 @@
 {
-  "generated": "2026-05-05T11:37:47Z",
-  "total_pass": 437,
+  "generated": "2026-05-05T12:00:17Z",
+  "total_pass": 464,
   "total_fail": 0,
   "suites": [
     {"name": "Phase 1: tokenizer/reader", "pass": 79, "fail": 0},
@@ -12,6 +12,7 @@
     {"name": "Phase 3: interactive-debugger", "pass": 7, "fail": 0},
     {"name": "Phase 4: CLOS", "pass": 41, "fail": 0},
     {"name": "Phase 4: geometry", "pass": 12, "fail": 0},
-    {"name": "Phase 4: mop-trace", "pass": 13, "fail": 0}
+    {"name": "Phase 4: mop-trace", "pass": 13, "fail": 0},
+    {"name": "Phase 5: macros+LOOP", "pass": 27, "fail": 0}
   ]
 }