conformance: migrate go onto shared driver (dict, 609/609 parity)

Go has the same structure as erlang: suites load into one session and each
exposes a pass counter plus a *count* (total) counter rather than a fail
counter. MODE=dict fits — each suite's runner is a dict literal
{:passed P :failed (- count P) :total count}. No driver change; conformance.conf
+ 3-line shim, historical scoreboard schema preserved.

Parity verified 609/609 (0 fail), every suite matching baseline.

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

lib/go/conformance.conf

@@ -0,0 +1,65 @@
+# Go-on-SX conformance config — sourced by lib/guest/conformance.sh.
+#
+# Like erlang: suites load into one session and each exposes a pass counter and
+# a *count* (total) counter, not a fail counter. dict mode fits — each runner is
+# a dict literal computing :failed as count - pass.
+
+LANG_NAME=go
+MODE=dict
+
+PRELOADS=(
+  lib/guest/lex.sx
+  lib/guest/ast.sx
+  lib/guest/pratt.sx
+  lib/go/lex.sx
+  lib/go/parse.sx
+  lib/go/types.sx
+  lib/go/sched.sx
+  lib/go/eval.sx
+  lib/go/std/strings.sx
+  lib/go/std/strconv.sx
+)
+
+# name:file:(runner) — runner is a dict literal {:passed :failed :total}.
+SUITES=(
+  "lex:lib/go/tests/lex.sx:{:passed go-test-pass :failed (- go-test-count go-test-pass) :total go-test-count}"
+  "parse:lib/go/tests/parse.sx:{:passed go-parse-test-pass :failed (- go-parse-test-count go-parse-test-pass) :total go-parse-test-count}"
+  "types:lib/go/tests/types.sx:{:passed go-types-test-pass :failed (- go-types-test-count go-types-test-pass) :total go-types-test-count}"
+  "eval:lib/go/tests/eval.sx:{:passed go-eval-test-pass :failed (- go-eval-test-count go-eval-test-pass) :total go-eval-test-count}"
+  "runtime:lib/go/tests/runtime.sx:{:passed go-rt-test-pass :failed (- go-rt-test-count go-rt-test-pass) :total go-rt-test-count}"
+  "stdlib:lib/go/tests/stdlib.sx:{:passed go-std-test-pass :failed (- go-std-test-count go-std-test-pass) :total go-std-test-count}"
+  "e2e:lib/go/tests/e2e.sx:{:passed go-e2e-test-pass :failed (- go-e2e-test-count go-e2e-test-pass) :total go-e2e-test-count}"
+)
+
+# Preserve the historical scoreboard schema so consumers of
+# lib/go/scoreboard.json keep working.
+emit_scoreboard_json() {
+  local n=${#GC_NAMES[@]} i status
+  printf '{\n'
+  printf '  "language": "go",\n'
+  printf '  "total_pass": %d,\n' "$GC_TOTAL_PASS"
+  printf '  "total": %d,\n' "$GC_TOTAL"
+  printf '  "suites": ['
+  for ((i=0; i<n; i++)); do
+    [ "$i" -gt 0 ] && printf ','
+    status="ok"; [ "${GC_FAIL[$i]}" -gt 0 ] && status="fail"
+    printf '\n    {"name":"%s","pass":%d,"total":%d,"status":"%s"}' \
+      "${GC_NAMES[$i]}" "${GC_PASS[$i]}" "${GC_TOTAL_S[$i]}" "$status"
+  done
+  printf '\n  ]\n'
+  printf '}\n'
+}
+
+emit_scoreboard_md() {
+  local n=${#GC_NAMES[@]} i marker
+  printf '# Go-on-SX Scoreboard\n\n'
+  printf '**Total: %d / %d tests passing**\n\n' "$GC_TOTAL_PASS" "$GC_TOTAL"
+  printf '|  | Suite | Pass | Total |\n'
+  printf '|---|---|---|---|\n'
+  for ((i=0; i<n; i++)); do
+    marker="✅"; [ "${GC_FAIL[$i]}" -gt 0 ] && marker="❌"
+    printf '| %s | %s | %d | %d |\n' \
+      "$marker" "${GC_NAMES[$i]}" "${GC_PASS[$i]}" "${GC_TOTAL_S[$i]}"
+  done
+  printf '\nGenerated by `lib/go/conformance.sh`.\n'
+}