Add HTTP print API for packing list and sign-off receipt

- core/printing.py: SumatraPDF silent print backend (dry_run, timeout, error capture)
- core/print_document.py: orchestrate generate() + print, per-report paper size, printer fallback
- core/print_api.py: FastAPI POST /api/print + GET /api/health, HTTPBearer auth, English Swagger at /api/docs
- serve.py: uvicorn entrypoint
- config: printers/print/api sections in settings.yaml + core/settings.py
- requirements.txt: add fastapi, uvicorn
- .gitignore: ignore logs/

core/print_document.py

@@ -0,0 +1,61 @@
+"""打印编排：生成报表 PDF -> 送打印机。
+
+复用现有 run.generate() 完成「查询→装配→渲染→PDF→页脚盖印」全链路，
+再调用 core.printing 把 PDF 静默打印到默认/指定打印机。
+"""
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+PROJECT_ROOT = Path(__file__).resolve().parent.parent
+if str(PROJECT_ROOT) not in sys.path:
+    sys.path.insert(0, str(PROJECT_ROOT))
+
+# run.py 在项目根，生成逻辑已验证；此处直接复用，不改动 run.py
+import run  # noqa: E402
+
+from core.settings import settings  # noqa: E402
+from core import printing  # noqa: E402
+
+VALID_REPORTS = ("packing_list", "sign_receipt")
+
+
+def print_document(
+    report_type: str,
+    params: dict,
+    printer: str | None = None,
+    dry_run: bool = False,
+) -> dict:
+    """生成报表 PDF 并打印。
+
+    :param report_type: packing_list | sign_receipt
+    :param params: 报表参数（如 paichan_no/box_no 或 receipt_no）
+    :param printer: 指定打印机名；为 None 时用 settings.printers.default
+    :param dry_run: True 时只构造打印命令不真正执行（用于验证链路）
+    :return: 结构化结果（含 pdf 路径、打印命令、ok 状态）
+    """
+    if report_type not in VALID_REPORTS:
+        raise ValueError(f"未知报表类型：{report_type}（支持 {list(VALID_REPORTS)}）")
+
+    # 1. 生成 PDF（run.generate 内部已做 required 参数校验与 DB 查询）
+    output = run._default_output(report_type, params)
+    out_path = run.generate(report_type, params, output)
+
+    # 2. 选打印机与纸张（装箱单 A5 横向 / 签收单 A4 纵向）
+    target_printer = printer or settings.printers.default
+    paper_settings = settings.print.settings_by_report.get(
+        report_type, settings.print.default_settings
+    )
+
+    # 3. 打印
+    result = printing.print_pdf(
+        pdf_path=out_path,
+        printer=target_printer,
+        settings=paper_settings,
+        sumatrapdf_path=settings.print.sumatrapdf_path,
+        dry_run=dry_run,
+    )
+    result["report_type"] = report_type
+    result["params"] = params
+    return result