test(joinir): Phase 129 P0 - add LLVM EXE smoke for Phase 128

- Add phase128_if_only_partial_assign_normalized_llvm_exe.sh
- VM+LLVM parity for if-only partial assign pattern
- Expected output: 2 (print(2) in then branch)

Regression verified:
- phase103_if_only_llvm_exe.sh: PASS
- phase118_loop_nested_if_merge_llvm_exe.sh: PASS

tools/smokes/v2/profiles/integration/apps/phase128_if_only_partial_assign_normalized_llvm_exe.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+# Phase 128: if-only partial assign (Normalized, LLVM EXE parity)
+#
+# Verifies that Phase 128 Assign(int literal) + If works in LLVM EXE:
+# - x=1; flag=1; if flag==1 { return 2 } return 1
+# - Assign statements update env
+# - Dev-only: NYASH_JOINIR_DEV=1 HAKO_JOINIR_STRICT=1
+#
+# Note: Full join_k continuation not yet implemented. This tests basic assign lowering.
+
+source "$(dirname "$0")/../../../lib/test_runner.sh"
+source "$(dirname "$0")/../../../lib/llvm_exe_runner.sh"
+export SMOKES_USE_PYVM=0
+require_env || exit 2
+
+llvm_exe_preflight_or_skip || exit 0
+
+# Phase 97/98/100 SSOT: plugin dlopen check → build only if needed → dlopen recheck.
+FILEBOX_SO="$NYASH_ROOT/plugins/nyash-filebox-plugin/libnyash_filebox_plugin.so"
+MAPBOX_SO="$NYASH_ROOT/plugins/nyash-map-plugin/libnyash_map_plugin.so"
+STRINGBOX_SO="$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=(
+  "FileBox|$FILEBOX_SO|nyash-filebox-plugin"
+  "MapBox|$MAPBOX_SO|nyash-map-plugin"
+  "StringBox|$STRINGBOX_SO|nyash-string-plugin"
+  "ConsoleBox|$CONSOLEBOX_SO|nyash-console-plugin"
+  "IntegerBox|$INTEGERBOX_SO|nyash-integer-plugin"
+)
+LLVM_PLUGIN_BUILD_LOG="/tmp/phase128_if_only_plugin_build.log"
+llvm_exe_ensure_plugins_or_fail || exit 1
+
+INPUT_HAKO="$NYASH_ROOT/apps/tests/phase128_if_only_partial_assign_normalized_min.hako"
+OUTPUT_EXE="$NYASH_ROOT/tmp/phase128_if_only_llvm_exe"
+
+EXPECTED=$'2'
+EXPECTED_LINES=1
+LLVM_BUILD_LOG="/tmp/phase128_if_only_build.log"
+if llvm_exe_build_and_run_numeric_smoke; then
+  test_pass "phase128_if_only_partial_assign_normalized_llvm_exe: output matches expected (2)"
+else
+  exit 1
+fi