chore(state): update STATE.a2ml — C2 reversibility complete

Marks C2 reversibility as landed (commit a6b9e83), clears the stale
blockers list, and updates critical-next-actions to the one remaining
item: WASM backend review for extern-coproc lowering.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: hyperpolymath

.machine_readable/6a2/STATE.a2ml

@@ -7,7 +7,7 @@ project = "julia-the-viper"
 version = "0.0.1"
 last-updated = "2026-04-27"
 status = "active"
-session = "2026-04-27 — coproc Phase 2+4 landed; PataCL Phases 1-4 complete"
+session = "2026-04-27 — C2 reversibility complete; all three session tasks (A/C/B) landed"
 
 [project-context]
 name = "Julia The Viper"
@@ -29,19 +29,16 @@ milestones = [
   "LSP server — DONE (tower-lsp integration)",
   "coprocessor support design — DONE (ADRs 0001-0006, 13 decisions closed 2026-04-19)",
   "coprocessor support implementation — DONE (Phase 2+4, 2026-04-27)",
-  "v2 reversibility C1 Phase 1 — COMPLETE (2026-04-27): execute_inverse added; reverse { x += v } = subtraction; 7 RV tests"
+  "v2 reversibility C1 Phase 1 — COMPLETE (2026-04-27): execute_inverse added; reverse { x += v } = subtraction; 7 RV tests",
+  "v2 reversibility C2 — COMPLETE (2026-04-27): reversible { } -> tok / reverse tok / abandon tok; ReversalToken(u64) opaque ID; token linearity enforced; 5 C2 tests; typechecker + cli sexpr both updated"
 ]
 
 [blockers-and-issues]
-issues = [
-  "v2 reversibility C1 Phase 1 implementation not yet started — uncommitted design files from earlier session"
-]
+issues = []
 
 [critical-next-actions]
 actions = [
-  "Zig FFI + Idris2 ABI lowering for live coproc decls (unblocks ExternCoprocNotYetLowered at call sites)",
-  "v2 reversibility C2: add `reversible { } -> tok` / `reverse tok` / `abandon tok` grammar + ReversalToken value",
-  "Review WASM backend for extern-coproc lowering (now unblocked)"
+  "Review WASM backend for extern-coproc lowering (ExternCoprocNotYetLowered at call sites — coproc_lower.rs generates stubs but WASM path untested)"
 ]
 
 [maintenance-status]
@@ -54,7 +51,8 @@ sessions = [
   { date = "2026-04-12", subject = "v2 reversibility design — 5 decisions closed" },
   { date = "2026-04-19", subject = "coprocessor pata pathway designed — ADRs 0001-0005 + 0006 (Delta pivot to PataCL)" },
   { date = "2026-04-27", subject = "PataCL Phases 1-4 complete; JtV Phase 2 landed (extern coproc grammar, CoprocNamespace, phase-boundary error, 12/12 coproc_tests.rs); conformance corpus CC1-CC7 (7/7); jtv-cli ExternCoproc fix" },
-  { date = "2026-04-27", subject = "Phase A: Zig FFI + Idris2 ABI lowering (coproc_lower.rs, 6 CL tests); Phase C: PataCL self-hosting (conformance/patacl-self.pata, 8 SH tests in patacl); Phase B: v2 reversibility C1 (execute_inverse added, reverse { } = subtraction, 7 RV tests)" }
+  { date = "2026-04-27", subject = "Phase A: Zig FFI + Idris2 ABI lowering (coproc_lower.rs, 6 CL tests); Phase C: PataCL self-hosting (conformance/patacl-self.pata, 8 SH tests in patacl); Phase B: v2 reversibility C1 (execute_inverse added, reverse { } = subtraction, 7 RV tests)" },
+  { date = "2026-04-27", subject = "C2 reversibility: reversible { } -> tok / reverse tok / abandon tok; ReversalToken(u64) opaque-ID token store; token linearity; typechecker + cli sexpr arms; 5 C2 tests green; commit a6b9e83" }
 ]
 
 [design-artefact-locations]