feat(admin): 比价记录 debug 页后端——补全链路 + DB 迁移

model/schema 的 debug 字段已在 4ee6de2 起头,本次补完整条链路:
- repo upsert 存客户端环境/性能字段;端点同机拉 pricebot llm_calls 落库 + 算 llm次数/重试
- schema 加 platform_results 透传(admin「卡在哪一步」从 raw_payload 读)
- admin 比价记录查询接口(按 user_id/phone 列表分页 + 详情含 llm_calls)
- 迁移 comparison_debug_fields: 给 comparison_record 加环境/性能/llm_calls 列(全 nullable)

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

alembic/versions/comparison_debug_fields.py

@@ -0,0 +1,54 @@
+"""comparison_record: 客户端环境 / 性能统计 / LLM 明细 debug 字段
+
+Revision ID: comparison_debug_fields
+Revises: cps_activity_image
+Create Date: 2026-06-17 22:00:00.000000
+
+给 admin 比价记录 debug 页新增采集列，全部 nullable(旧记录 / 未发版客户端为 NULL，向后兼容)：
+- 客户端环境: device_*/rom_*/android_*/app_version*/source_app_version/经纬度
+- 过程统计: total_ms/step_count/llm_call_count/retry_count
+- LLM 明细: llm_calls(JSONB，server 按 trace_id 同机拉 pricebot 落库)
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+
+revision: str = "comparison_debug_fields"
+down_revision: Union[str, Sequence[str], None] = "cps_activity_image"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+_JSONB = sa.JSON().with_variant(postgresql.JSONB(), "postgresql")
+
+
+def upgrade() -> None:
+    op.add_column("comparison_record", sa.Column("device_model", sa.String(64), nullable=True))
+    op.add_column("comparison_record", sa.Column("device_manufacturer", sa.String(64), nullable=True))
+    op.add_column("comparison_record", sa.Column("rom_vendor", sa.String(32), nullable=True))
+    op.add_column("comparison_record", sa.Column("rom_name", sa.String(32), nullable=True))
+    op.add_column("comparison_record", sa.Column("rom_version", sa.Integer(), nullable=True))
+    op.add_column("comparison_record", sa.Column("android_version", sa.String(16), nullable=True))
+    op.add_column("comparison_record", sa.Column("android_sdk", sa.Integer(), nullable=True))
+    op.add_column("comparison_record", sa.Column("app_version", sa.String(32), nullable=True))
+    op.add_column("comparison_record", sa.Column("app_version_code", sa.Integer(), nullable=True))
+    op.add_column("comparison_record", sa.Column("source_app_version", sa.String(32), nullable=True))
+    op.add_column("comparison_record", sa.Column("longitude", sa.Float(), nullable=True))
+    op.add_column("comparison_record", sa.Column("latitude", sa.Float(), nullable=True))
+    op.add_column("comparison_record", sa.Column("total_ms", sa.Integer(), nullable=True))
+    op.add_column("comparison_record", sa.Column("step_count", sa.Integer(), nullable=True))
+    op.add_column("comparison_record", sa.Column("llm_call_count", sa.Integer(), nullable=True))
+    op.add_column("comparison_record", sa.Column("retry_count", sa.Integer(), nullable=True))
+    op.add_column("comparison_record", sa.Column("llm_calls", _JSONB, nullable=True))
+
+
+def downgrade() -> None:
+    for col in (
+        "llm_calls", "retry_count", "llm_call_count", "step_count", "total_ms",
+        "latitude", "longitude", "source_app_version", "app_version_code",
+        "app_version", "android_sdk", "android_version", "rom_version",
+        "rom_name", "rom_vendor", "device_manufacturer", "device_model",
+    ):
+        op.drop_column("comparison_record", col)