feat: 重组为标准 skill 包结构 + 修复 verify.sh bash 3.2 兼容

- 新增 .claude/skills/new-project/SKILL.md（标准 skill 格式）
- install-skill.sh 安装时组装 SKILL.md + verify.sh，单一源无重复
- verify.sh 改用索引数组替代 declare -A，兼容 macOS bash 3.2
- log_pass/log_skip 显式 return 0，避免 set -e 下非 verbose 误退出
- README 改为 skill 优先；补全 copier.yml/scripts/template 入库

template/backend/pyproject.toml.jinja

@@ -0,0 +1,60 @@
+[project]
+name = "{{ project_slug }}-backend"
+version = "0.1.0"
+description = "{{ description }} — backend service"
+requires-python = ">={{ python_version }}"
+dependencies = [
+    "fastapi",
+    "uvicorn[standard]",
+    "sqlalchemy[asyncio]",
+{%- if database == 'sqlite' %}
+    "aiosqlite",
+    "alembic",
+{%- elif database == 'postgresql' %}
+    "asyncpg",
+    "alembic",
+{%- endif %}
+    "loguru",
+    "pydantic-settings",
+    "websockets",
+]
+
+[dependency-groups]
+dev = [
+    "pytest",
+    "httpx",
+    "pytest-asyncio",
+    "pytest-cov",
+    "mypy",
+    "ruff",
+    "pip-audit",
+]
+
+[tool.ruff.lint]
+select = ["E", "F", "N", "T20", "I", "C901", "ANN", "S", "PLR"]
+ignore = ["ANN101", "ANN102"]
+
+[tool.ruff.lint.per-file-ignores]
+"tests/**" = ["ANN"]
+
+[tool.mypy]
+strict = true
+ignore_missing_imports = true
+
+[tool.pytest.ini_options]
+addopts = "--cov=src --cov-report=term-missing --cov-fail-under=80"
+asyncio_mode = "auto"
+
+[tool.importlinter]
+root_packages = ["src"]
+
+[[tool.importlinter.contracts]]
+name = "Layered architecture"
+type = "layers"
+layers = ["src.infrastructure", "src.application", "src.domain"]
+
+[[tool.importlinter.contracts]]
+name = "Domain zero IO"
+type = "forbidden"
+source_modules = ["src.domain"]
+forbidden_modules = ["fastapi", "sqlalchemy", "httpx", "subprocess"]