refactor(wsl): унифицирована логика hproxy.local и добавлена миграция legacy boot command

- Зачем:
  - setup-hproxy.sh удалял запись из hosts до проверки gateway — при ошибке hosts ломался.
  - update_hproxy() дублировала логику скрипта с багами и не тестировалась.
  - legacy inline boot command в wsl.conf не мигрировался автоматически.
- Что:
  - setup-hproxy.sh: безопасный порядок (gateway → hosts), set -e, экранированная точка в sed.
  - update_hproxy() заменена на thin wrapper с проверкой wsl.conf и ошибок sudo.
  - install.sh: интерактивная замена legacy boot command, детекция существующих [boot] command,
    принимает русскую «у» наравне с «y».
  - README.md: описаны три сценария (WSL NAT, WSL mirrored — host-side resolution, native Linux).
  - добавлены тесты: existing boot command preserved, legacy command migration hint.
- Проверка:
  - bash tests/test_install.sh
  - ./install.sh (интерактивно, ответить «y» на миграцию legacy command)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/test_install.sh

@@ -236,6 +236,57 @@ test_wsl_noninteractive_skips_file_changes() {
   printf '%s' "$output" | grep -Fq 'Добавьте вручную:' || fail "Expected manual WSL hint"
 }
 
+test_wsl_noninteractive_existing_boot_command_is_preserved() {
+  local fixture repo_root home_dir wsl_conf output
+  fixture="$(setup_fixture)"
+  repo_root="$fixture/repo"
+  home_dir="$fixture/home"
+  wsl_conf="$fixture/wsl.conf"
+  mkdir -p "$home_dir"
+  cat > "$wsl_conf" <<'EOF'
+[boot]
+command = "/usr/local/bin/existing.sh"
+EOF
+
+  output="$(
+    run_install "$repo_root" "$home_dir" \
+      env WSL_DISTRO_NAME=Ubuntu INSTALL_INTERACTIVE_MODE=never WSL_CONF_PATH="$wsl_conf"
+  )"
+
+  assert_file_contains "$wsl_conf" 'command = "/usr/local/bin/existing.sh"'
+  if grep -Fq 'setup-hproxy.sh' "$wsl_conf"; then
+    fail "Expected existing boot command to stay untouched"
+  fi
+  printf '%s' "$output" | grep -Fq 'уже содержит [boot] command' || fail "Expected warning about existing boot command"
+  if printf '%s' "$output" | grep -Fq 'Добавьте вручную:'; then
+    fail "Did not expect manual add hint when [boot] command already exists"
+  fi
+}
+
+test_wsl_legacy_boot_command_suggests_migration() {
+  local fixture repo_root home_dir wsl_conf output command_line
+  fixture="$(setup_fixture)"
+  repo_root="$fixture/repo"
+  home_dir="$fixture/home"
+  wsl_conf="$fixture/wsl.conf"
+  mkdir -p "$home_dir"
+  cat > "$wsl_conf" <<'EOF'
+[boot]
+command = "ip route show default | awk '{print $3 \" hproxy.local\"}' >> /etc/hosts"
+EOF
+  command_line="command = \"$repo_root/scripts/setup-hproxy.sh\""
+
+  output="$(
+    run_install "$repo_root" "$home_dir" \
+      env WSL_DISTRO_NAME=Ubuntu INSTALL_INTERACTIVE_MODE=never WSL_CONF_PATH="$wsl_conf"
+  )"
+
+  assert_file_contains "$wsl_conf" 'command = "ip route show default | awk '\''{print $3 \" hproxy.local\"}'\'' >> /etc/hosts"'
+  printf '%s' "$output" | grep -Fq 'legacy boot command' || fail "Expected legacy boot command warning"
+  printf '%s' "$output" | grep -Fq 'Рекомендуется заменить' || fail "Expected migration hint to replace legacy command"
+  printf '%s' "$output" | grep -Fq "$command_line" || fail "Expected suggested setup-hproxy.sh command"
+}
+
 test_wsl_interactive_adds_boot_command() {
   local fixture repo_root home_dir wsl_conf command_line
   fixture="$(setup_fixture)"
@@ -289,6 +340,8 @@ main() {
   test_broken_claude_symlink_does_not_fail
   test_absolute_symlinks_in_home_do_not_break_install
   test_wsl_noninteractive_skips_file_changes
+  test_wsl_noninteractive_existing_boot_command_is_preserved
+  test_wsl_legacy_boot_command_suggests_migration
   test_wsl_interactive_adds_boot_command
   test_wsl_existing_boot_command_is_preserved