diff --git a/.beads/interactions.jsonl b/.beads/interactions.jsonl
index 3a37e4a..58b7f5f 100644
--- a/.beads/interactions.jsonl
+++ b/.beads/interactions.jsonl
@@ -20,3 +20,5 @@
 {"id":"int-8cd2e476","kind":"field_change","created_at":"2026-06-04T21:28:16.906665Z","actor":"Yogthos","issue_id":"jolt-y29","extra":{"field":"status","new_value":"closed","old_value":"open","reason":"Closed"}}
 {"id":"int-6042189d","kind":"field_change","created_at":"2026-06-04T23:20:46.565771Z","actor":"Yogthos","issue_id":"jolt-ns4","extra":{"field":"status","new_value":"closed","old_value":"open","reason":"Done across 3 rounds (pushed a0c9696): build-time mutable/immutable toggle, structural-sharing persistent vectors (32-way trie), and persistent O(1)-prepend linked lists. Plus bit-clear/get-method and a batch of missing core fns. conformance 206/206, features 78/78, jank 120."}}
 {"id":"int-80df5ed4","kind":"field_change","created_at":"2026-06-05T03:35:42.672628Z","actor":"Yogthos","issue_id":"jolt-i3g","extra":{"field":"status","new_value":"closed","old_value":"open","reason":"Done — SCI bootstrap now loads 422/422 with 0 failures. Fixed deftype protocol-method registration, with-meta on functions, select-keys over vectors, require :as+:refer, defmethod-on-fn; added clojure.set/join and host-module stubs. test-load-sci asserts 0 failures."}}
+{"id":"int-b296d941","kind":"field_change","created_at":"2026-06-05T05:02:01.433529Z","actor":"Yogthos","issue_id":"jolt-do7","extra":{"field":"status","new_value":"closed","old_value":"open","reason":"Fixed: PHM/PHS canonicalize collection keys for value-based hashing/comparison; map literals & assoc promote to phm on collection keys; frequencies/group-by use phm base; set = is value-based. Also fixed set literals not evaluating elements and the REPL phm printer. Spec cases added. (commit pushed next)"}}
+{"id":"int-885ca071","kind":"field_change","created_at":"2026-06-05T05:02:24.324962Z","actor":"Yogthos","issue_id":"jolt-e4p","extra":{"field":"status","new_value":"closed","old_value":"open","reason":"Won't-fix: backreferences and lookbehind are not expressible in a PEG engine (jolt regex compiles to Janet PEG); named groups are rare. Documented as unsupported in README's Regex section. Reopen if a concrete need arises."}}
diff --git a/.beads/issues.jsonl b/.beads/issues.jsonl
index 721c067..42c2415 100644
--- a/.beads/issues.jsonl
+++ b/.beads/issues.jsonl
@@ -12,12 +12,12 @@
 {"_type":"issue","id":"jolt-40n","title":"HIGH: update/update-in/assoc-in fail on map literals (struct)","status":"closed","priority":2,"issue_type":"bug","owner":"yogthos@gmail.com","created_at":"2026-06-04T18:09:56Z","created_by":"Yogthos","updated_at":"2026-06-04T18:40:42Z","closed_at":"2026-06-04T18:40:42Z","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-ytt","title":"HIGH: str semantics — (str nil)='nil' should be '', (str :b)='b' should be ':b'","status":"closed","priority":2,"issue_type":"bug","owner":"yogthos@gmail.com","created_at":"2026-06-04T18:09:56Z","created_by":"Yogthos","updated_at":"2026-06-04T18:33:45Z","closed_at":"2026-06-04T18:33:45Z","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-9sb","title":"HIGH: destructuring gaps (nested seq, :strs, nested map, fn-param)","status":"closed","priority":2,"issue_type":"bug","owner":"yogthos@gmail.com","created_at":"2026-06-04T18:09:55Z","created_by":"Yogthos","updated_at":"2026-06-04T18:31:24Z","closed_at":"2026-06-04T18:31:24Z","dependency_count":0,"dependent_count":0,"comment_count":0}
-{"_type":"issue","id":"jolt-do7","title":"phm-typed maps as set elements / map keys hash by identity","description":"A map produced via hash-map/assoc (a Janet table/phm) used as a set element or map key hashes by identity, so #{{:a 1}} (struct elem) != #{(hash-map :a 1)} (phm elem) and such elements aren't retrievable by value. Map literals (structs) work. Needs value-based hashing for phm keys in PHM/PHS. Edge case; spec covers literal-map cases.","status":"open","priority":3,"issue_type":"bug","owner":"yogthos@gmail.com","created_at":"2026-06-05T04:07:50Z","created_by":"Yogthos","updated_at":"2026-06-05T04:07:50Z","dependency_count":0,"dependent_count":0,"comment_count":0}
+{"_type":"issue","id":"jolt-do7","title":"phm-typed maps as set elements / map keys hash by identity","description":"A map produced via hash-map/assoc (a Janet table/phm) used as a set element or map key hashes by identity, so #{{:a 1}} (struct elem) != #{(hash-map :a 1)} (phm elem) and such elements aren't retrievable by value. Map literals (structs) work. Needs value-based hashing for phm keys in PHM/PHS. Edge case; spec covers literal-map cases.","status":"closed","priority":3,"issue_type":"bug","owner":"yogthos@gmail.com","created_at":"2026-06-05T04:07:50Z","created_by":"Yogthos","updated_at":"2026-06-05T05:02:01Z","closed_at":"2026-06-05T05:02:01Z","close_reason":"Fixed: PHM/PHS canonicalize collection keys for value-based hashing/comparison; map literals \u0026 assoc promote to phm on collection keys; frequencies/group-by use phm base; set = is value-based. Also fixed set literals not evaluating elements and the REPL phm printer. Spec cases added. (commit pushed next)","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-7dy","title":"MED: compiler path lacks IFn dispatch (collections-as-fn) — only interpreter fixed","status":"closed","priority":3,"issue_type":"bug","owner":"yogthos@gmail.com","created_at":"2026-06-04T18:10:00Z","created_by":"Yogthos","updated_at":"2026-06-04T19:56:36Z","closed_at":"2026-06-04T19:56:36Z","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-90c","title":"MED: filter/take-while not lazy — infinite-seq (take N (filter p (range))) loops","status":"closed","priority":3,"issue_type":"bug","owner":"yogthos@gmail.com","created_at":"2026-06-04T18:10:00Z","created_by":"Yogthos","updated_at":"2026-06-04T18:56:26Z","closed_at":"2026-06-04T18:56:26Z","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-7n5","title":"MED: REPL display — def/defn should print #'ns/name; lazy-seq printer realizes only head ((0 \u003cfunction\u003e))","status":"closed","priority":3,"issue_type":"bug","owner":"yogthos@gmail.com","created_at":"2026-06-04T18:09:59Z","created_by":"Yogthos","updated_at":"2026-06-04T18:55:11Z","closed_at":"2026-06-04T18:55:11Z","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-h0n","title":"MED: missing core fns — letfn fnil trampoline doseq cycle partition-all reductions dedupe keep-indexed map-indexed transduce reduce-kv assoc-in peek subvec read-string format","status":"closed","priority":3,"issue_type":"feature","owner":"yogthos@gmail.com","created_at":"2026-06-04T18:09:58Z","created_by":"Yogthos","updated_at":"2026-06-04T18:57:26Z","closed_at":"2026-06-04T18:57:26Z","dependency_count":0,"dependent_count":0,"comment_count":0}
-{"_type":"issue","id":"jolt-e4p","title":"regex: lookbehind, backreferences (\\1), named groups (?\u003cn\u003e) unsupported (rare); engine is parse-\u003ePEG with backtracking","status":"open","priority":4,"issue_type":"feature","owner":"yogthos@gmail.com","created_at":"2026-06-04T20:23:39Z","created_by":"Yogthos","updated_at":"2026-06-04T20:23:39Z","dependency_count":0,"dependent_count":0,"comment_count":0}
+{"_type":"issue","id":"jolt-e4p","title":"regex: lookbehind, backreferences (\\1), named groups (?\u003cn\u003e) unsupported (rare); engine is parse-\u003ePEG with backtracking","status":"closed","priority":4,"issue_type":"feature","owner":"yogthos@gmail.com","created_at":"2026-06-04T20:23:39Z","created_by":"Yogthos","updated_at":"2026-06-05T05:02:24Z","closed_at":"2026-06-05T05:02:24Z","close_reason":"Won't-fix: backreferences and lookbehind are not expressible in a PEG engine (jolt regex compiles to Janet PEG); named groups are rare. Documented as unsupported in README's Regex section. Reopen if a concrete need arises.","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-cn4","title":"regex engine is a common subset (PEG-backed); lookaround/backrefs/named-groups unsupported","status":"closed","priority":4,"issue_type":"feature","owner":"yogthos@gmail.com","created_at":"2026-06-04T19:27:50Z","created_by":"Yogthos","updated_at":"2026-06-04T20:23:37Z","closed_at":"2026-06-04T20:23:37Z","close_reason":"Closed","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-4zg","title":"char type: chars represented as 1-char strings; (seq \"ab\") yields strings not \\a \\b — deferred design decision","status":"closed","priority":4,"issue_type":"feature","owner":"yogthos@gmail.com","created_at":"2026-06-04T19:27:49Z","created_by":"Yogthos","updated_at":"2026-06-04T19:41:39Z","closed_at":"2026-06-04T19:41:39Z","dependency_count":0,"dependent_count":0,"comment_count":0}
 {"_type":"issue","id":"jolt-l8f","title":"transduce + transducer arities (1-arg map/filter/take); niche, deferred","status":"closed","priority":4,"issue_type":"feature","owner":"yogthos@gmail.com","created_at":"2026-06-04T18:57:27Z","created_by":"Yogthos","updated_at":"2026-06-04T19:48:04Z","closed_at":"2026-06-04T19:48:04Z","dependency_count":0,"dependent_count":0,"comment_count":0}