Phase 4: deftype/defrecord completion

- evaluator.janet: fix set! to handle (.-field obj) shorthand
  Previously only recognized (. obj -field) format
- core.janet: rewrite core-defrecord to emit (deftype ...) instead of
  plain def with array-map constructor
- core.janet: fix core-map? to recognize deftype table instances
  (and returns last truthy, not boolean true — wrap in if)
- core.janet: fix core-count to skip :jolt/deftype key for records
- core.janet: add ->TypeName arrow factory that calls TypeName.
  constructor via Clojure form emission
- 11 new tests: deftype fields/mutation/instance?, defrecord
  construction/map-behavior/fields/factories, record equality
- map->TypeName factory deferred (needs get/symbol resolution fix)
- 317 tests pass, 0 failures

.dirge/skills/.usage.json

@@ -1,16 +1,26 @@
 {
   "jolt-dev": {
     "created_by": "agent",
-    "use_count": 30,
-    "view_count": 45,
-    "patch_count": 37,
-    "last_used_at": "2026-06-02T22:24:09.648320+00:00",
-    "last_viewed_at": "2026-06-02T22:24:09.636430+00:00",
-    "last_patched_at": "2026-06-02T22:24:40.254179+00:00",
+    "use_count": 32,
+    "view_count": 47,
+    "patch_count": 40,
+    "last_used_at": "2026-06-03T00:55:18.036371+00:00",
+    "last_viewed_at": "2026-06-03T00:55:18.017806+00:00",
+    "last_patched_at": "2026-06-03T00:55:51.227868+00:00",
     "created_at": "2026-06-01T21:26:06.614465+00:00",
     "state": "active",
     "pinned": false
   },
+  "jpm-build": {
+    "created_by": "agent",
+    "use_count": 0,
+    "view_count": 15,
+    "patch_count": 0,
+    "last_viewed_at": "2026-06-02T21:03:17.897587+00:00",
+    "created_at": "2026-06-01T20:56:39.144222+00:00",
+    "state": "active",
+    "pinned": false
+  },
   "jolt-bootstrap": {
     "created_by": "agent",
     "use_count": 9,
@@ -25,24 +35,14 @@
   },
   "jolt-compiler": {
     "created_by": "agent",
-    "use_count": 4,
-    "view_count": 8,
-    "patch_count": 6,
-    "last_used_at": "2026-06-02T22:24:09.679583+00:00",
-    "last_viewed_at": "2026-06-02T22:24:09.655249+00:00",
-    "last_patched_at": "2026-06-02T21:40:55.723354+00:00",
+    "use_count": 5,
+    "view_count": 9,
+    "patch_count": 7,
+    "last_used_at": "2026-06-03T00:55:56.946140+00:00",
+    "last_viewed_at": "2026-06-03T00:55:56.935595+00:00",
+    "last_patched_at": "2026-06-03T00:56:15.725835+00:00",
     "created_at": "2026-06-02T17:54:38.690279+00:00",
     "state": "active",
     "pinned": false
-  },
-  "jpm-build": {
-    "created_by": "agent",
-    "use_count": 0,
-    "view_count": 15,
-    "patch_count": 0,
-    "last_viewed_at": "2026-06-02T21:03:17.897587+00:00",
-    "created_at": "2026-06-01T20:56:39.144222+00:00",
-    "state": "active",
-    "pinned": false
   }
 }