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/memory/MEMORY.md

@@ -7,3 +7,5 @@ Phase 2 (PersistentHashMap): Live in src/jolt/phm.janet — separate module impo
 Macro expansion: resolve-macro at analyze time → expand → re-analyze. Loop: (do (var _loop_N nil) (set _loop_N (fn [params] body)) (_loop_N vals...)). Recur: emits (loop-name args...) via :loop-name in AST.
 §
 Test files: test/phase6-final.janet (47 tests, 58 assertions — collections, math, predicates, comparison, seq ops, special forms, macros, complex nesting). Phase 1 tests appended to test/compiler-test.janet (ns accessors, ns form extensions). All 317 tests pass.
+§
+Phase 3 (Var system): find-var (ctx-based, resolve-q/nq symbol), alter-meta!, reset-meta!, var-get/var-set/var?/alter-var-root all in types.janet + evaluator dispatch arms + core-bindings wrappers. core-meta fixed: (var? x) branch → var-meta, struct? branch → :meta. 10 tests pass.

.dirge/memory/PITFALLS.md

@@ -1,7 +1,7 @@
-core-renames MUST match actual function names in core.janet. `"-"`→`core-sub` NOT `core--`. `"fn?"` was missing entirely (caused silent nil). Missing entries → symbol treated as unknown global, returns nil. When adding: grep core.janet for actual `(defn core-XXX)` name, add to BOTH core-renames (string table) and core-fn-values (fn value table).
-§
 Bare tuples in Janet's `eval` are function calls: `(eval [1 2 3])` tries to call `1` as function. Always emit `['tuple 1 2 3]` or `(tuple 1 2 3)` in data-structure emitter. Similarly, `(eval (try body (sym handler)))` fails because `catch` is not a Janet special form — must be `(try body ([sym] handler))`. Discovered during Phase 5/6 compiler work.
 §
 Duplicate function definitions in the same file cause hard-to-diagnose "unknown symbol" errors. In compiler.janet, emit-quote-str was defined twice (once before emit-ast dispatch, once before emit-expr section). The second definition compiled but the first was used by emit-ast dispatch — causing "unknown symbol raw-form->janet". Always grep for the fn name before adding a new definition.
 §
 Janet break can't be used inside let blocks — break returns from the innermost loop, and in a let, there's no loop. Pattern: use (var found nil) + (while ... (if condition (do (set found val) (break)))) then check found after loop.
+§
+core-binding macro: use array-map (plain struct) NOT hash-map/PHM for the binding frame. PHM's phm-get doesn't work with push-thread-bindings' var-get lookup. Symptom: "error: dynamic binding" with no useful message. Fix: emit (array-map [var sym] val ...) instead of (hash-map ...).