feat(agent,report): 会话持久化与画像注入、报告反馈与预约留资——PM/开发双Agent迭代1-3

- agent: ag_conversation/ag_message 表(迁移0007),上下文组装注入最近报告画像摘要
  (report.profile.latest_profile_summary 经 apps 层闭包注入,同层不互调),历史带最近
  AGENT_HISTORY_TURNS=10 轮;POST/GET /agent/conversations 与消息历史接口
- agent 修复:ChatRequest.conversation_id 改 str(雪花ID超2^53,JS Number丢精度);
  _build_context 挪进 reserve commit 后同一 try,异常走 refund 兜底
- report: rp_feedback(维度反馈 upsert,认同率/修正率 SQL 可算,T-P3-21 最小版——
  L1 记忆未建,不回写结论)+ rp_reservation(预约留资幂等,T-P3-22,预约率口径
  行数/full_report.card_view 去重曝光,门槛≥8%),迁移0008
- 测试:全量 606 passed;ruff/mypy/lint-imports 全绿;E2E 真实 deepseek-v4-flash 验证
  画像注入与历史携带

tests/unit/test_agent_context.py

@@ -0,0 +1,67 @@
+"""上下文组装（架构 §7.2 步骤③）的纯逻辑测试：画像注入与历史截尾。"""
+
+from __future__ import annotations
+
+from packages.agent.context import (
+    PROFILE_SUMMARY_MAX_CHARS,
+    build_context_messages,
+    build_profile_message,
+)
+from packages.llm.types import Message
+
+
+class TestBuildContextMessages:
+    def test_profile_first_then_history(self) -> None:
+        history = [
+            Message(role="user", content="第一句"),
+            Message(role="assistant", content="第一答"),
+        ]
+        messages = build_context_messages(
+            profile_summary='{"dimensions":[]}', history=history, history_turns=10
+        )
+        assert len(messages) == 3
+        assert messages[0].role == "system"
+        assert '{"dimensions":[]}' in messages[0].content
+        assert [m.role for m in messages[1:]] == ["user", "assistant"]
+        assert [m.content for m in messages[1:]] == ["第一句", "第一答"]
+
+    def test_no_profile_degrades_to_history_only(self) -> None:
+        """无画像用户（FR-AGT-10 降级）：不注入画像消息，历史照常携带。"""
+        history = [Message(role="user", content="hi")]
+        messages = build_context_messages(profile_summary=None, history=history, history_turns=10)
+        assert len(messages) == 1
+        assert messages[0].role == "user"
+
+    def test_empty_profile_string_treated_as_absent(self) -> None:
+        messages = build_context_messages(profile_summary="", history=[], history_turns=10)
+        assert messages == []
+
+    def test_history_tail_kept_by_turns(self) -> None:
+        """一轮 = user+assistant 两条；N=2 时只留最近 4 条，截头不截尾。"""
+        history: list[Message] = []
+        for i in range(5):
+            history.append(Message(role="user", content=f"u{i}"))
+            history.append(Message(role="assistant", content=f"a{i}"))
+        messages = build_context_messages(profile_summary=None, history=history, history_turns=2)
+        assert [m.content for m in messages] == ["u3", "a3", "u4", "a4"]
+
+    def test_zero_turns_drops_history(self) -> None:
+        history = [Message(role="user", content="u0")]
+        messages = build_context_messages(profile_summary=None, history=history, history_turns=0)
+        assert messages == []
+
+    def test_history_message_content_capped(self) -> None:
+        history = [Message(role="user", content="x" * 5000)]
+        messages = build_context_messages(profile_summary=None, history=history, history_turns=10)
+        assert len(messages[0].content) == 2000
+
+
+class TestBuildProfileMessage:
+    def test_wraps_summary_as_system_message(self) -> None:
+        message = build_profile_message("{}")
+        assert message.role == "system"
+        assert message.content.endswith("{}")
+
+    def test_budget_constant_within_token_budget(self) -> None:
+        """画像摘要预算 ≤ 500 token（README 预算表），按 ~1.6 字符/token 折算。"""
+        assert PROFILE_SUMMARY_MAX_CHARS <= 500 * 1.6