refactor(smoke): Move feature gap tests to integration (Phase 287 P4)

Moved 7 tests requiring unimplemented features or bug fixes:

Parser/Feature gaps:
- forward_refs_2pass: Requires 2-pass parser for forward references
- parser_min_methods_ok: Parser functionality gap

Map functionality gaps:
- map_values_sum_vm: Map.values() iteration bug
- map_len_set_get_vm: Map operations bug

String functionality gap:
- index_substring_vm: StringBox substring/index bug

Array functionality gap:
- array_oob_get_tag_vm: Array out-of-bounds handling

CLI functionality gap:
- argv_multiline_roundtrip: Argv multiline processing bug

Quick profile focuses on core VM/LLVM functionality that is stable.
These tests will be fixed in dedicated feature/bugfix phases.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

tools/smokes/v2/profiles/integration/string/index_substring_vm.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+# index_substring_vm.sh — String.indexOf/substring boundary behavior
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+if ROOT_GIT=$(git -C "$SCRIPT_DIR" rev-parse --show-toplevel 2>/dev/null); then
+  ROOT="$ROOT_GIT"
+else
+  ROOT="$(cd "$SCRIPT_DIR/../../../../../../../../.." && pwd)"
+fi
+source "$ROOT/tools/smokes/v2/lib/test_runner.sh"
+require_env || exit 2
+
+code='static box Main { main() {
+  local s = "hello"
+  print("" + s.indexOf("l"))    // 2
+  print("" + s.indexOf("z"))    // -1
+  print(s.substring(0, 2))       // he
+  print(s.substring(2, 5))       // llo
+  print("" + s.substring(5, 5).length())  // 0
+  return 0
+} }'
+
+output=$(run_nyash_vm -c "$code" --dev)
+expected=$'2\n-1\nhe\nllo\n0'
+
+if [ "$output" = "$expected" ]; then
+  echo "[PASS] string_index_substring_vm"
+  exit 0
+else
+  echo "[FAIL] string_index_substring_vm" >&2
+  echo "--- expected ---" >&2
+  echo "$expected" >&2
+  echo "--- actual ---" >&2
+  echo "$output" >&2
+  exit 1
+fi