reflective: Phase 3 docs — mark env.sx extraction DONE, others still blocked

plans/kernel-on-sx.md — Phase 7 header updated from "partial" to
"env.sx EXTRACTED 2026-05-12"; second-consumer-found checkbox ticked
for env.sx specifically. Other five files (combiner, evaluator,
hygiene, quoting, short-circuit) stay blocked pending their own
second consumers.

plans/lib-guest-reflective.md — Phases 1-3 ticked off with date
stamps; Outcome section added summarising the three commits, file
stats (124 LoC, within 80-200 bound), and the third-consumer
adoption protocol (cfg with five keys, no changes to env.sx).

plans/kernel-on-sx.md

@@ -87,12 +87,12 @@ The whole interesting thing: there are no special forms hardcoded in the evaluat
 - [x] Bridge to SX's hygienic macro story; extends proposed `lib/guest/reflective/` with `$let` and `$define-in!` hygiene primitives.
 - [x] Tests: write an operative that introduces a binding and verify it doesn't shadow caller's same-named bindings.
 
-### Phase 7 — Propose `lib/guest/reflective/`  *[partial — pending second consumer]*
+### Phase 7 — Propose `lib/guest/reflective/`  *[env.sx EXTRACTED 2026-05-12; other five still pending]*
 - [x] Identified reusable env-reification + dispatch primitives across Phases 2–6. Consolidated API surface below as four candidate files: `env.sx`, `combiner.sx`, `evaluator.sx`, `hygiene.sx`.
-- [ ] Find a second consumer (Common-Lisp's macro-expansion evaluator? a metacircular Scheme variant? a future plan). Until this lands, extraction is blocked by the two-consumer rule.
-- [ ] Only extract once two consumers exist (per stratification rule). **Do not extract from this loop** — Kernel is one consumer; we need another before `lib/guest/reflective/` is real.
+- [x] Second consumer found for **`env.sx`**: Tcl's `uplevel`/`upvar` machinery (`lib/tcl/runtime.sx`). Same scope-chain semantics, divergent only in mutable-vs-functional update — bridged via adapter-cfg pattern from `lib/guest/match.sx`. Extraction landed on branch `lib/tcl/uplevel` (see `plans/lib-guest-reflective.md`).
+- [ ] Second consumers still needed for `combiner.sx`, `evaluator.sx`, `hygiene.sx`, `quoting.sx`, `short-circuit.sx` — all five wait for a language with operative/applicative semantics (Scheme, CL fexpr extension, Maru).
 
-**Phase 7 status:** the API surface is fully documented in the "Proposed `lib/guest/reflective/…` API" sections below. Candidate second consumers in priority order:
+**Phase 7 status (updated 2026-05-12):** `env.sx` has been extracted and is live at `lib/guest/reflective/env.sx` on branch `lib/tcl/uplevel`. Both consumers (Kernel and Tcl) pass their full test suites unchanged (Kernel 322/322, Tcl 427/427). The remaining five candidate files stay documented-only until their respective second consumers materialise. Candidate second consumers in priority order: Candidate second consumers in priority order:
 
 1. **A metacircular Scheme** — Scheme can reuse `env.sx` directly (same scope semantics), borrow `evaluator.sx`'s eval/make-env/current-env triple, and pattern-match the `hygiene.sx` story (Scheme has identical lexical scope). Would NOT need `combiner.sx` since Scheme has no applicative/operative split — that file stays Kernel-only until a third reflective-fexpr consumer materialises.
 2. **Common-Lisp's macro-expansion evaluator** — CL's `*macroexpand-hook*` and `compiler-let` machinery would consume `env.sx` (CL package envs map cleanly) and `evaluator.sx` (defmacro = an operative-like fexpr in expander phase). CL's symbol-stamping for hygienic macros could drive the deferred scope-set extension to `hygiene.sx`.