plans: Phase 6 verified 399/399 — vwait :: deadlock fixed via tcl-var-lookup-or-nil

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

plans/tcl-sx-completion.md

@@ -314,6 +314,17 @@ updates made inside Tcl proc bodies — only `:commands` was forwarded.
 Now forwards the full set. Surfaced when socket-async made
 fileevent-from-inside-proc the canonical pattern.
 
+**Bug fix landed alongside:** `vwait ::var` was infinite-looping because
+`vwait` used `frame-lookup` directly, which doesn't honour `::` global
+routing. So after `set ::done fired` (which routes the write to the root
+frame), `vwait ::done` kept reading the local frame and never saw the
+change. Added `tcl-var-lookup-or-nil` helper that mirrors `tcl-var-get`'s
+`::` routing but returns nil instead of erroring on missing vars; vwait
+and `info exists` both use it now.
+
+**Total: 399/399 green** (parse 67, eval 169, error 39, namespace 22,
+coro 20, idiom 82).
+
 ---
 
 ## Suggested order
@@ -332,6 +343,7 @@ becomes a lasting SX contribution used by every future hosted language.
 
 _Newest first._
 
+- 2026-05-08: Phase 6 verified — 399/399 (parse 67, eval 169, error 39, namespace 22, coro 20, idiom 82). Fixed vwait `::var` infinite loop via tcl-var-lookup-or-nil helper; info exists also uses it now.
 - 2026-05-07: Phase 6e exec — exec-process SX primitive (Unix.create_process+waitpid, captures stdout, errors on non-zero exit with stderr) + Tcl `exec cmd arg...`; +3 idiom tests
 - 2026-05-07: Phase 6d scan/format — printf-spec + scan-spec SX primitives wrapping OCaml Printf/Scanf via Scanf.format_from_string; Tcl format rewritten to dispatch via printf-spec; scan is real walker; supports d/i/u/x/X/o/c/s/f/e/E/g/G/% with width/precision/flags; +7 idiom tests
 - 2026-05-07: Phase 6c dict additions — dict lappend / remove / filter -key (rest of dict was already implemented); +3 idiom tests