feat(internal): 启动确认窗 agent 兜底样本落盘(pricebot 回写)

- 新增内部端点 POST /internal/launch-confirm-sample(X-Internal-Secret 鉴权):
  pricebot 对没见过文案的启动确认窗用 LLM 兜底放行后,把样本(host 包 / 弹窗树 /
  LLM plan / 设备 locale 机型)回写落 launch_confirm_sample 表,供研发人工沉淀回
  pricebot 规则 yaml
- 配套: model LaunchConfirmSample + schema + repo(都上报不去重) + alembic 迁移
  launch_confirm_sample_table(down_revision=cps_wx_user) + main 注册 router +
  models/__init__ 登记
- docs: 后端技术实现.md 加 §6.5 pricebot 回写内部端点说明

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/api/internal/launch_confirm.py

@@ -0,0 +1,63 @@
+"""启动确认窗兜底样本内部上报端点(pricebot → app-server)。
+
+pricebot 的 launch_confirm_agent 每次靠 LLM 兜底放行一个"静态 PROFILES 没认出"的跨 App
+启动确认窗时,把完整样本 POST 到这里落库。**不是给客户端的接口**:不走用户 JWT,靠
+server 间共享密钥头 `X-Internal-Secret` 校验(== settings.INTERNAL_API_SECRET)。密钥未配置
+(默认空)时直接 503,避免裸奔写端点。
+
+研发定期人工把 exec_success=true 的样本沉淀进 pricebot 的 launch_confirm.PROFILES。
+"""
+from __future__ import annotations
+
+import hmac
+import logging
+from typing import Annotated
+
+from fastapi import APIRouter, Header, HTTPException, status
+
+from app.api.deps import DbSession
+from app.core.config import settings
+from app.repositories import launch_confirm_sample as repo
+from app.schemas.launch_confirm_sample import (
+    LaunchConfirmSampleIn,
+    LaunchConfirmSampleOut,
+)
+
+logger = logging.getLogger("shagua.internal.launch_confirm")
+
+router = APIRouter(prefix="/internal", tags=["internal"])
+
+
+def _check_secret(x_internal_secret: str | None) -> None:
+    """共享密钥校验。未配置 → 503(挡裸奔写端点);不匹配 → 401(常量时间比较)。"""
+    configured = settings.INTERNAL_API_SECRET
+    if not configured:
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail="internal api not configured",
+        )
+    if not x_internal_secret or not hmac.compare_digest(x_internal_secret, configured):
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="invalid internal secret",
+        )
+
+
+@router.post(
+    "/launch-confirm-sample",
+    response_model=LaunchConfirmSampleOut,
+    summary="启动确认窗兜底样本上报(pricebot→app-server,落 launch_confirm_sample)",
+)
+def report_launch_confirm_sample(
+    payload: LaunchConfirmSampleIn,
+    db: DbSession,
+    x_internal_secret: Annotated[str | None, Header()] = None,
+) -> LaunchConfirmSampleOut:
+    _check_secret(x_internal_secret)
+    sid = repo.insert_sample(db, payload)
+    logger.info(
+        "launch_confirm_sample id=%d host=%s locale=%s success=%s trace=%s",
+        sid, payload.host_package, payload.system_locale,
+        payload.exec_success, payload.trace_id,
+    )
+    return LaunchConfirmSampleOut(id=sid)