test(joinir): Phase 131 loop(true) break-once fixture + VM/LLVM smokes

Add minimal fixture and smoke tests for loop(true) break-once pattern:

**Fixture**:
- apps/tests/phase131_loop_true_break_once_min.hako
  - Pattern: x=0; loop(true) { x=1; break }; return x
  - Expected: return value 1 (exit code 1)

**Smokes**:
- tools/smokes/v2/profiles/integration/apps/phase131_loop_true_break_once_vm.sh
  - VM backend test with dev-only flags
- tools/smokes/v2/profiles/integration/apps/phase131_loop_true_break_once_llvm_exe.sh
  - LLVM EXE backend test with plugin gating

**Note**: Smokes currently fail (execution path not yet wired).
Structure implementation only - follow-up phase will wire execution.

Related: Phase 131 P0 (Normalized shadow structure)

apps/tests/phase131_loop_true_break_once_min.hako

@@ -0,0 +1,24 @@
+// Phase 131 P0: loop(true) break-once minimal fixture
+//
+// Purpose: Test loop(true) { <assign>* ; break } in Normalized shadow
+// Expected output: 1
+//
+// Structure:
+//   x = 0         // pre-loop init
+//   loop(true) {  // condition is Bool literal true
+//       x = 1     // body assignment
+//       break     // break at end
+//   }
+//   return x      // return updated value
+
+static box Main {
+    main() {
+        local x
+        x = 0
+        loop(true) {
+            x = 1
+            break
+        }
+        return x
+    }
+}

tools/smokes/v2/profiles/integration/apps/phase131_loop_true_break_once_llvm_exe.sh

@@ -0,0 +1,35 @@
+#!/bin/bash
+# Phase 131 P0: loop(true) break-once (LLVM EXE parity)
+# Pattern: loop(true) { x = 1; break } → return x (should be 1)
+
+source "$(dirname "$0")/../../../lib/test_runner.sh"
+source "$(dirname "$0")/../../../lib/llvm_exe_runner.sh"
+export SMOKES_USE_PYVM=0
+require_env || exit 2
+
+llvm_exe_preflight_or_skip || exit 0
+
+# Phase 131: minimal plugin set (StringBox, ConsoleBox, IntegerBox only)
+STRINGBOX_SO="$NYASH_ROOT/plugins/nyash-string-plugin/libnyash_string_plugin.so"
+CONSOLEBOX_SO="$NYASH_ROOT/plugins/nyash-console-plugin/libnyash_console_plugin.so"
+INTEGERBOX_SO="$NYASH_ROOT/plugins/nyash-integer-plugin/libnyash_integer_plugin.so"
+
+LLVM_REQUIRED_PLUGINS=(
+  "StringBox|$STRINGBOX_SO|nyash-string-plugin"
+  "ConsoleBox|$CONSOLEBOX_SO|nyash-console-plugin"
+  "IntegerBox|$INTEGERBOX_SO|nyash-integer-plugin"
+)
+LLVM_PLUGIN_BUILD_LOG="/tmp/phase131_loop_true_break_once_plugin_build.log"
+llvm_exe_ensure_plugins_or_fail || exit 1
+
+INPUT_HAKO="$NYASH_ROOT/apps/tests/phase131_loop_true_break_once_min.hako"
+OUTPUT_EXE="$NYASH_ROOT/tmp/phase131_loop_true_break_once_llvm_exe"
+
+EXPECTED=$'1'
+EXPECTED_LINES=1
+LLVM_BUILD_LOG="/tmp/phase131_loop_true_break_once_build.log"
+if llvm_exe_build_and_run_numeric_smoke; then
+  test_pass "phase131_loop_true_break_once_llvm_exe: output matches expected (1)"
+else
+  exit 1
+fi

tools/smokes/v2/profiles/integration/apps/phase131_loop_true_break_once_vm.sh

@@ -0,0 +1,61 @@
+#!/bin/bash
+# Phase 131 P0: loop(true) break-once (Normalized shadow, VM)
+#
+# Verifies that loop(true) { <assign>* ; break } works in Normalized:
+# - x = 0 → loop(true) { x = 1; break } → return x → 1
+# - Dev-only: NYASH_JOINIR_DEV=1 HAKO_JOINIR_STRICT=1
+
+source "$(dirname "$0")/../../../lib/test_runner.sh"
+source "$(dirname "$0")/../../../lib/output_validator.sh"
+export SMOKES_USE_PYVM=0
+require_env || exit 2
+
+PASS_COUNT=0
+FAIL_COUNT=0
+RUN_TIMEOUT_SECS=${RUN_TIMEOUT_SECS:-10}
+
+echo "[INFO] Phase 131 P0: loop(true) break-once (Normalized shadow, VM)"
+
+# Test 1: phase131_loop_true_break_once_min.hako
+echo "[INFO] Test 1: phase131_loop_true_break_once_min.hako"
+INPUT="$NYASH_ROOT/apps/tests/phase131_loop_true_break_once_min.hako"
+
+set +e
+OUTPUT=$(timeout "$RUN_TIMEOUT_SECS" env \
+  NYASH_DISABLE_PLUGINS=1 \
+  HAKO_JOINIR_STRICT=1 \
+  NYASH_JOINIR_DEV=1 \
+  "$NYASH_BIN" --backend vm "$INPUT" 2>&1)
+EXIT_CODE=$?
+set -e
+
+if [ "$EXIT_CODE" -eq 124 ]; then
+  echo "[FAIL] hakorune timed out (>${RUN_TIMEOUT_SECS}s)"
+  FAIL_COUNT=$((FAIL_COUNT + 1))
+elif [ "$EXIT_CODE" -eq 1 ]; then
+  # Phase 131: expected output is exit code 1 (return value)
+  EXPECTED=$'1'
+  if validate_numeric_output 1 "$EXPECTED" "$OUTPUT"; then
+    echo "[PASS] Output verified: 1 (exit code: $EXIT_CODE)"
+    PASS_COUNT=$((PASS_COUNT + 1))
+  else
+    echo "[INFO] output (tail):"
+    echo "$OUTPUT" | tail -n 50 || true
+    FAIL_COUNT=$((FAIL_COUNT + 1))
+  fi
+else
+  echo "[FAIL] hakorune failed with exit code $EXIT_CODE (expected 1)"
+  echo "[INFO] output (tail):"
+  echo "$OUTPUT" | tail -n 50 || true
+  FAIL_COUNT=$((FAIL_COUNT + 1))
+fi
+
+echo "[INFO] PASS: $PASS_COUNT, FAIL: $FAIL_COUNT"
+
+if [ "$FAIL_COUNT" -eq 0 ]; then
+  test_pass "phase131_loop_true_break_once_vm: All tests passed"
+  exit 0
+else
+  test_fail "phase131_loop_true_break_once_vm: $FAIL_COUNT test(s) failed"
+  exit 1
+fi