refactor(claude): settings.json отдан Claude Code, базовые настройки в settings.local.json

- Зачем:
  - Claude Code перезаписывает settings.json при каждом «always allow», что создавало
    конфликт с managed-копией из dotfiles при повторном запуске install.sh.
- Что:
  - settings.json удалён из репозитория, Claude Code владеет им полностью.
  - создан settings.local.json (базовые permissions + statusLine), деплоится через симлинк.
  - install.sh: копирование + шаблон заменены на ln -sf с бэкапом и guard для edge cases.
  - check.sh: проверка обновлена под симлинк вместо «файл + chmod 444».
  - тесты: старый тест копирования заменён на 4 новых (симлинк, бэкап, директория, stow-миграция).
- Проверка:
  - bash tests/test_install.sh (15 тестов).
  - bash agents/.agents/skills/dotfiles-check/check.sh.

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

tests/test_install.sh

@@ -101,23 +101,72 @@ test_fresh_install_uses_home_target() {
   assert_not_exists "$fixture/.bash_custom"
 }
 
-test_dirty_repo_settings_copy_uses_committed_version() {
+test_settings_local_is_symlinked_to_repo() {
   local fixture repo_root home_dir
   fixture="$(setup_fixture)"
   repo_root="$fixture/repo"
   home_dir="$fixture/home"
   mkdir -p "$home_dir"
 
-  chmod u+w "$repo_root/claude/.claude/settings.json"
-  cat > "$repo_root/claude/.claude/settings.json" <<'EOF'
-{"source":"working-tree"}
-EOF
+  run_install "$repo_root" "$home_dir" env WSL_DISTRO_NAME= INSTALL_INTERACTIVE_MODE=never >/tmp/test-install.out
 
-  FAKE_GIT_SHOW_CONTENT='{"source":"head"}' \
-    run_install "$repo_root" "$home_dir" env WSL_DISTRO_NAME= INSTALL_INTERACTIVE_MODE=never >/tmp/test-install.out
+  [ -L "$home_dir/.claude/settings.local.json" ] || fail "Expected settings.local.json to be a symlink"
+  local target
+  target="$(readlink -f "$home_dir/.claude/settings.local.json")"
+  local expected
+  expected="$(readlink -f "$repo_root/claude/.claude/settings.local.json")"
+  [ "$target" = "$expected" ] || fail "settings.local.json points to $target, expected $expected"
+}
 
-  assert_file_contains "$home_dir/.claude/settings.json" '"source":"head"'
-  assert_file_contains "$repo_root/claude/.claude/settings.json" '"source":"working-tree"'
+test_settings_local_backup_on_existing_file() {
+  local fixture repo_root home_dir
+  fixture="$(setup_fixture)"
+  repo_root="$fixture/repo"
+  home_dir="$fixture/home"
+  mkdir -p "$home_dir/.claude"
+  echo '{"model":"sonnet"}' > "$home_dir/.claude/settings.local.json"
+
+  run_install "$repo_root" "$home_dir" env WSL_DISTRO_NAME= INSTALL_INTERACTIVE_MODE=never >/tmp/test-install.out
+
+  [ -L "$home_dir/.claude/settings.local.json" ] || fail "Expected settings.local.json to become a symlink"
+  local backup
+  backup="$(find "$home_dir/.claude" -maxdepth 1 -name 'settings.local.json.bak.*' -print -quit)"
+  [ -n "$backup" ] || fail "Expected backup for existing settings.local.json"
+  assert_file_contains "$backup" '"model":"sonnet"'
+}
+
+test_settings_local_dir_is_skipped() {
+  local fixture repo_root home_dir
+  fixture="$(setup_fixture)"
+  repo_root="$fixture/repo"
+  home_dir="$fixture/home"
+  mkdir -p "$home_dir/.claude/settings.local.json"
+
+  run_install "$repo_root" "$home_dir" env WSL_DISTRO_NAME= INSTALL_INTERACTIVE_MODE=never >/tmp/test-install.out
+
+  [ -d "$home_dir/.claude/settings.local.json" ] || fail "Expected directory to be preserved (not replaced)"
+}
+
+test_stow_migration_preserves_legacy_settings_local() {
+  local fixture repo_root home_dir stow_target
+  fixture="$(setup_fixture)"
+  repo_root="$fixture/repo"
+  home_dir="$fixture/home"
+  mkdir -p "$home_dir"
+
+  # Simulate old stow layout: ~/.claude → repo dir
+  stow_target="$repo_root/claude/.claude"
+  ln -s "$stow_target" "$home_dir/.claude"
+  # Put a legacy settings.local.json in the stow target (would have been gitignored before)
+  echo '{"model":"opus"}' > "$stow_target/legacy-local.json"
+
+  run_install "$repo_root" "$home_dir" env WSL_DISTRO_NAME= INSTALL_INTERACTIVE_MODE=never >/tmp/test-install.out
+
+  [ -d "$home_dir/.claude" ] || fail "Expected ~/.claude to become a directory"
+  [ ! -L "$home_dir/.claude" ] || fail "Expected ~/.claude to stop being a symlink"
+  [ -L "$home_dir/.claude/settings.local.json" ] || fail "Expected settings.local.json symlink after migration"
+  # legacy-local.json should have been moved from stow dir to real ~/.claude
+  [ -f "$home_dir/.claude/legacy-local.json" ] || fail "Expected legacy file to be migrated"
 }
 
 test_rerun_does_not_duplicate_bashrc_line() {
@@ -332,7 +381,10 @@ main() {
   command -v stow >/dev/null 2>&1 || fail "stow is required for tests"
 
   test_fresh_install_uses_home_target
-  test_dirty_repo_settings_copy_uses_committed_version
+  test_settings_local_is_symlinked_to_repo
+  test_settings_local_backup_on_existing_file
+  test_settings_local_dir_is_skipped
+  test_stow_migration_preserves_legacy_settings_local
   test_rerun_does_not_duplicate_bashrc_line
   test_repairs_nested_skills_directory_bug
   test_preserves_nonempty_skills_directory