feat(billing): task bonus claim endpoint with idempotency and cap

POST /quota/tasks/{task_key}/claim：配置驱动任务注册表、
grant_bonus 纯域函数、ledger 幂等键防重、task_bonus_max 封顶（FR-BILL-03/04）。

实现：packages/domain/billing/quota.py 新增 BonusDecision/grant_bonus（mypy strict，
恰好到顶允许、超一格整体拒绝）、grant_idempotency_key、PERIOD_TYPES；
packages/billing/service.py 新增 claim_task_bonus（幂等快捷路径 → 行锁 → 封顶判定
→ 同事务更新 bonus_granted 并写 system_grant 流水，delta=0 且 balance_after 按
remaining 口径；IntegrityError 并发兜底回滚为 40910）；响应模型 TaskBonusClaimResponse
放新建的 packages/billing/schemas.py；路由挂在 apps/api/routers/quota.py，
rules 由 settings.task_bonus_rules 注入（amount 为占位值，产品定稿后改 env）。
测试：新增单测 11 个（封顶边界、amount<=0、不动 used、hard_cap 独立生效、
默认规则形状与 env 覆盖通路）；新增集成 4 个（领取+重复 40910+纯 DB 流水断言、
五类任务全部到账、未知任务 40410、amount=11>max=10 → 40310 且无新流水）。
门禁全绿：ruff check / ruff format --check / mypy 两段 / lint-imports；
单测 180 passed，集成 7 passed。

偏差说明：1) 任务文档提到的 BillingService._load_rule 实际名为 _require_rule，
   直接复用现有助手；2) packages/billing/repo.py 无需新增函数（现有
   get_ledger_by_idempotency_key/lock_or_create_quota/add_ledger 已覆盖本任务）；
   3) 文档设想的「TASK_BONUS_RULES_JSON 空值容错」经 env 源实测不成立——
   pydantic-settings 对 dict 字段先做 JSON 解码，空白字符串在 Settings 构造时即
   报错（共享校验器/config.py 属禁改，未动）；单测改为覆盖受支持的空配置形态 "{}"。

tests/integration/test_task_bonus.py

@@ -0,0 +1,190 @@
+"""任务奖励领取端到端（FR-BILL-03）：发放、幂等、封顶、流水.
+
+只依赖 PostgreSQL（额度与账本都在库里），不经过 Redis，也不触发任何 LLM
+调用 —— 与 test_vertical_slice.py 的 FakeProvider 思路一致：集成用例验证
+配额链路，不该花钱也不该受网络影响。
+"""
+
+from __future__ import annotations
+
+import json
+import os
+import uuid
+from collections.abc import AsyncIterator, Iterator
+from typing import Any
+
+import pytest
+
+
+def _infra_available() -> bool:
+    return bool(os.getenv("MEIDA_RUN_INTEGRATION"))
+
+
+pytestmark = [
+    pytest.mark.integration,
+    pytest.mark.skipif(
+        not _infra_available(),
+        reason="set MEIDA_RUN_INTEGRATION=1 with PostgreSQL and Redis running",
+    ),
+]
+
+
+@pytest.fixture
+async def client() -> AsyncIterator[Any]:
+    import httpx
+
+    from apps.api.main import create_app
+    from packages.shared.config import get_settings
+
+    app = create_app(get_settings())
+    transport = httpx.ASGITransport(app=app)
+    async with (
+        httpx.AsyncClient(transport=transport, base_url="http://test") as http,
+        app.router.lifespan_context(app),
+    ):
+        yield http
+
+
+async def _login(client: Any) -> tuple[dict[str, str], int]:
+    """dev-token：每个用例用独立 device_key，拿到的就是全新用户."""
+    resp = await client.post(
+        "/api/v1/auth/dev-token", json={"device_key": f"bonus-it-{uuid.uuid4().hex[:8]}"}
+    )
+    assert resp.json()["code"] == 0
+    data = resp.json()["data"]
+    return {"Authorization": f"Bearer {data['access_token']}"}, int(data["user_id"])
+
+
+async def _system_grant_rows(user_id: int) -> list[Any]:
+    """纯 DB 断言用：直接读 bl_ledger，不经过 HTTP 视图."""
+    from sqlalchemy import select
+
+    from packages.shared.db import session_scope
+    from packages.shared.models import Ledger
+
+    async with session_scope() as session:
+        result = await session.execute(
+            select(Ledger).where(Ledger.user_id == user_id, Ledger.tx_type == "system_grant")
+        )
+        return list(result.scalars().all())
+
+
+async def _quota_view(client: Any, headers: dict[str, str], quota_key: str) -> dict[str, Any]:
+    resp = await client.get("/api/v1/quota", headers=headers, params={"quota_key": quota_key})
+    assert resp.json()["code"] == 0
+    data: dict[str, Any] = resp.json()["data"]
+    return data
+
+
+async def test_claim_grants_immediately_and_repeats_are_rejected(client: Any) -> None:
+    headers, user_id = await _login(client)
+
+    claim = await client.post("/api/v1/quota/tasks/sign_in/claim", headers=headers)
+    assert claim.status_code == 200
+    body = claim.json()
+    assert body["code"] == 0
+    assert body["data"] == {
+        "task_key": "sign_in",
+        "quota_key": "agent_chat",
+        "amount": 1,  # 占位值；正式数值由产品定稿后改 TASK_BONUS_RULES_JSON
+        "bonus_granted": 1,
+        "remaining": 11,  # base_limit 10 + bonus 1 - used 0
+    }
+
+    # 发放即到账：额度视图立刻可见。
+    view = await _quota_view(client, headers, "agent_chat")
+    assert view["bonus_granted"] == 1
+    assert view["remaining"] == 11
+
+    # 同一任务同一周期重复 claim → 40910（FR-BILL-03 发放幂等）。
+    again = await client.post("/api/v1/quota/tasks/sign_in/claim", headers=headers)
+    assert again.status_code == 409
+    assert again.json()["code"] == 40910
+
+    # 纯 DB 断言：恰好一条 system_grant 流水，balance_after = base + bonus。
+    rows = await _system_grant_rows(user_id)
+    assert len(rows) == 1
+    assert rows[0].delta == 0
+    assert rows[0].status == "committed"
+    assert rows[0].reason == "sign_in"
+    assert rows[0].ref_type == "task_bonus"
+    assert rows[0].balance_after == 10 + 1
+    assert rows[0].idempotency_key.startswith(f"grant:{user_id}:sign_in:")
+
+    # 幂等拒绝不改变账面。
+    view = await _quota_view(client, headers, "agent_chat")
+    assert view["bonus_granted"] == 1
+
+
+async def test_all_five_frbill03_tasks_land_on_their_quotas(client: Any) -> None:
+    headers, user_id = await _login(client)
+
+    all_tasks = (
+        "sign_in",
+        "profile_complete",
+        "report_feedback",
+        "share_report",
+        "invite_friend",
+    )
+    for task_key in all_tasks:
+        resp = await client.post(f"/api/v1/quota/tasks/{task_key}/claim", headers=headers)
+        assert resp.status_code == 200, task_key
+        assert resp.json()["code"] == 0, task_key
+
+    # agent_chat 吃两个任务（sign_in + profile_complete）；tryon 吃两个；report_regen 一个。
+    chat = await _quota_view(client, headers, "agent_chat")
+    assert chat["bonus_granted"] == 2
+    assert chat["remaining"] == 12
+    tryon = await _quota_view(client, headers, "tryon")
+    assert tryon["bonus_granted"] == 2
+    assert tryon["remaining"] == 5  # base 3 + bonus 2（task_bonus_max=3 未触顶）
+    regen = await _quota_view(client, headers, "report_regen")
+    assert regen["bonus_granted"] == 1
+    assert regen["remaining"] == 2
+
+    rows = await _system_grant_rows(user_id)
+    assert len(rows) == 5
+    assert len({row.idempotency_key for row in rows}) == 5
+
+
+async def test_unknown_task_returns_40410(client: Any) -> None:
+    headers, _ = await _login(client)
+    resp = await client.post("/api/v1/quota/tasks/not_a_real_task/claim", headers=headers)
+    assert resp.status_code == 404
+    assert resp.json()["code"] == 40410
+
+
+@pytest.fixture
+def capped_rules(monkeypatch: pytest.MonkeyPatch) -> Iterator[None]:
+    """把 sign_in 的 amount 覆盖成 11（> agent_chat 的 task_bonus_max=10）.
+
+    monkeypatch.setenv + get_settings.cache_clear()（结束恢复），与 T1 的
+    settings 覆盖写法一致；依赖该 fixture 的用例会把 client 建在覆盖之后。
+    """
+    from packages.shared.config import get_settings
+
+    monkeypatch.setenv(
+        "TASK_BONUS_RULES_JSON",
+        json.dumps({"sign_in": {"quota_key": "agent_chat", "amount": 11, "claim_period": "day"}}),
+    )
+    get_settings.cache_clear()
+    try:
+        yield
+    finally:
+        monkeypatch.undo()
+        get_settings.cache_clear()
+
+
+async def test_claim_over_the_cap_is_rejected_without_any_ledger(
+    capped_rules: None, client: Any
+) -> None:
+    headers, user_id = await _login(client)
+
+    resp = await client.post("/api/v1/quota/tasks/sign_in/claim", headers=headers)
+    assert resp.status_code == 403
+    assert resp.json()["code"] == 40310
+
+    # 拒绝路径不写任何流水，bonus 也不动（FR-BILL-03 验收 3）。
+    assert await _system_grant_rows(user_id) == []
+    view = await _quota_view(client, headers, "agent_chat")
+    assert view["bonus_granted"] == 0

tests/unit/test_bonus_domain.py

@@ -0,0 +1,74 @@
+"""grant_bonus 纯域函数：封顶边界与不变量（FR-BILL-03）."""
+
+from __future__ import annotations
+
+import pytest
+
+from packages.domain.billing import quota
+
+
+def test_grant_up_to_the_cap_exactly_is_allowed() -> None:
+    # bonus + amount == max：恰好到顶，允许。
+    decision = quota.grant_bonus(quota.QuotaState(used=0, base_limit=10, bonus=9), 1, 10)
+    assert decision.allowed
+    assert decision.bonus == 10
+    assert decision.effective_limit == 20
+    assert decision.remaining == 20
+
+
+def test_grant_one_over_the_cap_is_rejected_as_a_whole() -> None:
+    # bonus + amount == max + 1：整体拒绝，不做部分发放。
+    state = quota.QuotaState(used=4, base_limit=10, bonus=9)
+    decision = quota.grant_bonus(state, 2, 10)
+    assert not decision.allowed
+    # 拒绝时保持发放前的值 —— 调用方不得据此落库。
+    assert decision.bonus == 9
+    assert decision.remaining == state.remaining
+    assert decision.effective_limit == state.effective_limit
+
+
+def test_zero_cap_rejects_every_grant() -> None:
+    # hd_export / report_basic 的 task_bonus_max=0：任务奖励一律拒绝。
+    decision = quota.grant_bonus(quota.QuotaState(used=0, base_limit=1), 1, 0)
+    assert not decision.allowed
+
+
+def test_grant_rejects_non_positive_amounts() -> None:
+    state = quota.QuotaState(used=0, base_limit=10)
+    with pytest.raises(ValueError, match="positive"):
+        quota.grant_bonus(state, 0, 10)
+    with pytest.raises(ValueError, match="positive"):
+        quota.grant_bonus(state, -1, 10)
+
+
+def test_grant_never_touches_used_or_base_limit() -> None:
+    # 任务奖励抬高的是额度不是用量：remaining 的增量恰好等于 amount。
+    state = quota.QuotaState(used=7, base_limit=10, bonus=2)
+    decision = quota.grant_bonus(state, 3, 10)
+    assert decision.allowed
+    assert decision.remaining - state.remaining == 3
+    assert decision.bonus == 5
+
+
+def test_task_bonus_cap_is_independent_of_hard_cap() -> None:
+    # 两道天花板独立生效：task_bonus_max 放行、hard_cap 把 effective_limit 削回来。
+    state = quota.QuotaState(used=0, base_limit=3, bonus=3, hard_cap=5)
+    decision = quota.grant_bonus(state, 3, 10)
+    assert decision.allowed  # bonus 6 <= task_bonus_max 10
+    assert decision.effective_limit == 5  # base 3 + bonus 6 被 hard_cap 削到 5
+    assert decision.remaining == 5
+
+
+def test_grant_key_is_derived_per_user_task_and_claim_period() -> None:
+    key = quota.grant_idempotency_key(
+        user_id=7, task_key="sign_in", claim_period_key="d:2026-08-14"
+    )
+    assert key == "grant:7:sign_in:d:2026-08-14"
+    # 派生键确定：同一周期重复 claim 得到同一个键，唯一约束才能兜底。
+    assert key == quota.grant_idempotency_key(
+        user_id=7, task_key="sign_in", claim_period_key="d:2026-08-14"
+    )
+    # 换周期换键：下个周期可以再领。
+    assert key != quota.grant_idempotency_key(
+        user_id=7, task_key="sign_in", claim_period_key="d:2026-08-15"
+    )

tests/unit/test_task_bonus_rules.py

@@ -0,0 +1,62 @@
+"""settings.task_bonus_rules 的形状与 env 通路（FR-BILL-03/04）.
+
+协调提交已把 ``task_bonus_rules`` 纳入 ``_parse_json_object`` 共享校验器，
+解析逻辑不再单独测；这里测默认值形状（每条配置必须能被 claim 路径安全消费）
+以及集成测试要依赖的 ``TASK_BONUS_RULES_JSON`` 覆盖通路。
+"""
+
+from __future__ import annotations
+
+import json
+
+import pytest
+
+from packages.domain.billing.quota import PERIOD_TYPES
+from packages.shared.config import Settings
+
+#: FR-BILL-03 的五类任务：签到、完善资料、反馈、分享、邀请。
+_FR_BILL_03_TASKS = (
+    "sign_in",
+    "profile_complete",
+    "report_feedback",
+    "share_report",
+    "invite_friend",
+)
+
+
+def _rules_without_env() -> dict[str, dict[str, object]]:
+    # _env_file=None：不读 .env，只看进程环境，保证断言的是代码内默认值。
+    return dict(Settings(_env_file=None).task_bonus_rules)
+
+
+def test_default_rules_cover_all_five_frbill03_tasks() -> None:
+    rules = _rules_without_env()
+    for task_key in _FR_BILL_03_TASKS:
+        assert task_key in rules, task_key
+
+
+def test_every_default_rule_entry_has_a_valid_shape() -> None:
+    for task_key, conf in _rules_without_env().items():
+        assert isinstance(conf, dict), task_key
+        quota_key = conf.get("quota_key")
+        assert isinstance(quota_key, str) and quota_key, task_key
+        amount = conf.get("amount")
+        assert isinstance(amount, int) and not isinstance(amount, bool), task_key
+        assert amount > 0, task_key  # 占位值 1，正式数值由产品定稿后改 env
+        assert conf.get("claim_period") in PERIOD_TYPES, task_key
+
+
+def test_rules_json_env_reaches_settings_via_alias(monkeypatch: pytest.MonkeyPatch) -> None:
+    # 集成测试用同一通路把 amount 覆盖成超限值验证封顶，这里先证明通路本身可用。
+    raw = json.dumps({"sign_in": {"quota_key": "agent_chat", "amount": 11, "claim_period": "day"}})
+    monkeypatch.setenv("TASK_BONUS_RULES_JSON", raw)
+    settings = Settings(_env_file=None)
+    assert settings.task_bonus_rules["sign_in"]["amount"] == 11
+
+
+def test_empty_rules_object_env_means_no_tasks(monkeypatch: pytest.MonkeyPatch) -> None:
+    # 关闭任务奖励的受支持形态是 "{}"：解析为空注册表，所有 claim 返回 40410，
+    # 服务照常启动。（空白字符串不是合法 JSON，pydantic-settings 在 Settings
+    # 构造时就地失败——那是共享校验器的行为，不归本任务改。）
+    monkeypatch.setenv("TASK_BONUS_RULES_JSON", "{}")
+    assert Settings(_env_file=None).task_bonus_rules == {}