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>

alembic/versions/launch_confirm_sample_table.py

@@ -0,0 +1,53 @@
+"""launch_confirm_sample table (启动确认窗 agent 兜底样本: LLM 放行的弹窗样本沉淀)
+
+Revision ID: launch_confirm_sample_table
+Revises: cps_wx_user
+Create Date: 2026-06-20 00:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = "launch_confirm_sample_table"
+down_revision: Union[str, Sequence[str], None] = "cps_wx_user"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "launch_confirm_sample",
+        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.text("(CURRENT_TIMESTAMP)"), nullable=False),
+        sa.Column("trace_id", sa.String(length=64), nullable=True),
+        sa.Column("device_id", sa.String(length=64), nullable=True),
+        sa.Column("host_package", sa.String(length=128), nullable=True),
+        sa.Column("target_app", sa.String(length=128), nullable=True),
+        sa.Column("system_locale", sa.String(length=32), nullable=True),
+        sa.Column("exec_success", sa.Boolean(), nullable=False),
+        sa.Column("dialog_title", sa.String(length=256), nullable=True),
+        # PG 上为 JSONB,其它(SQLite)为 JSON——与模型层 with_variant 对齐
+        sa.Column("payload", sa.JSON().with_variant(sa.dialects.postgresql.JSONB(), "postgresql"), nullable=True),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    with op.batch_alter_table("launch_confirm_sample", schema=None) as batch_op:
+        batch_op.create_index(batch_op.f("ix_launch_confirm_sample_created_at"), ["created_at"], unique=False)
+        batch_op.create_index(batch_op.f("ix_launch_confirm_sample_trace_id"), ["trace_id"], unique=False)
+        batch_op.create_index(batch_op.f("ix_launch_confirm_sample_device_id"), ["device_id"], unique=False)
+        batch_op.create_index(batch_op.f("ix_launch_confirm_sample_host_package"), ["host_package"], unique=False)
+        batch_op.create_index(batch_op.f("ix_launch_confirm_sample_system_locale"), ["system_locale"], unique=False)
+
+
+def downgrade() -> None:
+    with op.batch_alter_table("launch_confirm_sample", schema=None) as batch_op:
+        batch_op.drop_index(batch_op.f("ix_launch_confirm_sample_system_locale"))
+        batch_op.drop_index(batch_op.f("ix_launch_confirm_sample_host_package"))
+        batch_op.drop_index(batch_op.f("ix_launch_confirm_sample_device_id"))
+        batch_op.drop_index(batch_op.f("ix_launch_confirm_sample_trace_id"))
+        batch_op.drop_index(batch_op.f("ix_launch_confirm_sample_created_at"))
+
+    op.drop_table("launch_confirm_sample")