artdag: maude-bridge dag<->term adapter + 14 round-trip tests

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

plans/artdag-on-sx.md

@@ -31,7 +31,7 @@ edges.
 
 ## Status (rolling)
 
-`bash lib/artdag/conformance.sh` → **158/158** (10 suites: dag, analyze, plan, execute, optimize, fed, cost, serialize, stats, fault)
+`bash lib/artdag/conformance.sh` → **172/172** (11 suites: dag, analyze, plan, execute, optimize, fed, cost, serialize, stats, fault, maude-optimize)
 
 Base roadmap (Phases 1–6) COMPLETE. Now extending.
 
@@ -145,7 +145,7 @@ dedup) expressed as equations, where the optimised pipeline IS the normal form
 and confluence ⇒ a stable content id. Reimplement Phase-5 optimisation
 declaratively and prove it equivalent to the hand-written `optimize.sx`.
 
-- [ ] `lib/artdag/maude-bridge.sx` — adapter between an effect DAG node and a
+- [x] `lib/artdag/maude-bridge.sx` — adapter between an effect DAG node and a
   maude term: `(op, sorted-input-ids, params)` ⟷ `(mau/app op (args...))`.
   Params become constant subterms; for commutative ops use a maude AC operator
   so input order is irrelevant (mirror the content-id's order-insensitivity).
@@ -179,6 +179,21 @@ be an op token.
 
 ## Progress log
 
+- **2026-06-07 Phase 7 — maude-bridge** (maude-optimize suite 14/14, total 172/172).
+  `lib/artdag/maude-bridge.sx`: lossless adapter between an artdag effect DAG and a
+  maude term. `artdag/dag->term dag id` walks from a sink, emitting `(mau/app op
+  input-terms ++ meta)` per node; the trailing `artdag:meta` subterm carries params
+  (a `write-to-string` token) + a commutativity flag, so no side table is needed.
+  `artdag/term->dag` synthesizes build-entries (names `mb0…`) and re-runs
+  `artdag/build`, which recomputes content-ids (name-independent) and re-collapses
+  shared subterms — so `artdag/mb-roundtrip` is the identity on canonical form:
+  sink id, op, params, and the full node survive; commutative ids stay
+  order-insensitive; a diamond's shared node de-duplicates back to one (4→4).
+  Maude entry points used: `mau/app`/`mau/const`/`mau/op`/`mau/args`/`mau/app?`.
+  `conformance.sh` now gates the maude PRELOADS + bridge load to the maude-optimize
+  suite (other suites stay maude-free). Gotcha: `write-to-string`/`read` round-trips
+  keyword dicts but may reorder keys — fine, dicts compare structurally with `=`.
+
 - **Ext: public API facade** (`lib/artdag/api.sx`, total 158/158 unchanged).
   Reference index matching the datalog/persist convention: canonical load order +
   the full public surface across all 10 modules + `artdag/version`.