feat: persistent vector (working) + HAMT hash map (wip)

PersistentVector: 17-form .clj source, fully working.
- 32-way branching trie with tail optimization
- pv-conj, pv-nth, pv-assoc, pv-pop, vector?, vector constructor
- instance? check works on deftype tables
- .-field accessor syntax for deftype fields

api.janet: :mutable? compile flag for opt-out
- Default: persistent data structures loaded
- Pass {:mutable? true} to use Janet native types

Supporting changes (evaluator/core):
- 17 new primitives: bit ops, array ops, unchecked math, hash, cond
- loop macro, zero?, dec/inc, defn multi-arity
- instance? for deftype tables (get val :jolt/deftype)
- defrecord builds maps at expansion time
- .-field field access in default function application path

PersistentHashMap: 24-form HAMT source loads OK.
- BitmapIndexedNode/PersistentHashMap deftypes
- mask, bitpos, bit-count, index helpers
- phm-assoc/phm-get/phm-without/phm-contains? stubs
- bmn-assoc insert path structured, bitmap propagation wip

.dirge/memory/MEMORY.md

@@ -1,9 +1,11 @@
-SCI added as git submodule at `vendor/sci` (github.com/borkdude/sci). Path to SCI sources: `vendor/sci/src/sci/`. The original `/Users/yogthos/src/sci` path is now superseded.
+Janet bit-shift: `blshift` (left), `brshift` (right), `brushift` (unsigned right). `brushift` on negative numbers errors (out of range for 32-bit unsigned). No `lshift`/`rshift`/`urshift`.
 §
-Architecture decision: Jolt is a Janet-hosted SCI with minimal bootstrapping. Jolt's evaluator + reader form the runtime; SCI's `clojure.core` namespace is populated by loading all 9 SCI source files. `sci.core/eval-string` is replaced with a Jolt-native version: `(defn jolt-eval-string [s &opt opts] (eval-form ctx @{} @[{:jolt/type :symbol :ns nil :name "do"} (parse-string s)]))`. This bypasses SCI's internal interpreter/parser/analyzer pipeline entirely, avoiding the edamame dependency.
+Janet `get` does NOT follow table prototypes set by `table/setproto`. Use custom walker: `(var t bindings) (while t (when (in t key) (return (in t key))) (set t (table/getproto t)))`. Must use mutable result variable — `return` from loop inside `fn` body doesn't work in Janet.
 §
-gensym in core.janet: uses `@{}` mutable table counter `gensym_counter`. Takes optional prefix string (default "G__"). `core-doto` uses gensym for the object symbol, expands to `(let* [sym obj] (. sym method args)... sym)`. `core-defrecord` generates `->TypeName` positional constructor. `core-name` returns string for keywords (`(string kw)`) or symbol name field.
+`instance?` extended for deftype: checks `:jolt/deftype` tag on struct instances. `set!` extended for field mutation: `(set! (. obj -field) val)` → `(put obj (keyword "field") val)`. Both patterns used by persistent vector implementation (`.arr`, `.cnt`, `.tail`, etc. access).
 §
-SCI added as git submodule at vendor/sci. Load path: vendor/sci/src/sci/*.cljc (not impl/lang.cljc — lang.cljc is at top level under src/sci/). Internal namespaces that need edamame shims: interop.cljc, opts.cljc, parser.cljc, analyzer.cljc, interpreter.cljc. Parser requires edamame.core and clojure.tools.reader.reader-types stubs.
+Core primitives for persistent data structures: `alength`, `aget`, `aset`, `aclone`, `object-array`, `int-array`, `to-array` (array interop); `bit-and/or/xor/not`, `bit-shift-left/right`, `unsigned-bit-shift-right` (trie indexing); `int` uses `math/trunc`; `unchecked-inc/dec/add/subtract` for unchecked math; `hash` delegates to Janet built-in `hash`. All registered in `core-bindings`.
 §
-Constructor call resolution (ClassName. syntax) is handled in evaluator's default function application path at line 579-587: checks if symbol name ends with "." (chr 46), strips the dot, resolves the type symbol, and applies the constructor. This means `(sci.lang.Var. 1 2 3)` resolves `sci.lang.Var.` → looks up `sci.lang/Var` → gets the deftype constructor function → applies args. No special form needed.
+`and`/`or` macros: `(and x y)` → `(let* [and__x x] (if and__x (and y) and__x))`. `(or x y)` → `(let* [or__x x] (if or__x or__x (or y)))`. Registered as macros in core-macro-names. `defrecord` macro builds key-value pairs at expansion time using `array-map` constructor, not `interleave` at eval time.
+§
+SCI added as git submodule at `vendor/sci` (https://github.com/borkdude/sci.git). Clone with `git submodule update --init`. 317/317 forms load from 9 core files. Internal namespaces (interop, parser, opts) partially loaded — parser.cljc needs `utils/new-var` (calls `sci.lang.Var.` constructor) and `edamame/normalize-opts` stubs.