fix(policy): use container-compatible imports (drop app. prefix)

프로덕션 컨테이너는 /app 을 cwd 로 실행하고 import 는 `from api...`,
`from core...`, `from workers...` 처럼 무접두 스타일을 사용한다.
PR-A 내부 import 가 `from app.policy...`, `from app.ai.envelope` 로
되어 있어서 컨테이너에서 ModuleNotFoundError 발생.

변경:
- app/policy/*.py: `from app.policy.X` → `from policy.X`
- app/services/prompt_versions.py: lazy import 도 `from policy.prompt_render`
- app/ai/envelope.py: 영향 없음 (내부 import 없음)
- tests/policy/*.py: 모두 `from policy.X` / `from ai.envelope` 로 통일
- tests/policy/conftest.py: 로컬 pytest 용 sys.path.insert(app/) 추가
  (MacBook 에서 repo-root 기준 실행 시 app/ 를 package root 로 취급)

CI: pytest tests/policy/ -q → 98 passed (로컬, 동일 결과)
프로덕션: docker exec fastapi python -c "from policy.loader import load_policy" → OK

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/policy/conftest.py

@@ -2,19 +2,27 @@
 
 실제 repo root 의 domain_policy.yaml 을 그대로 로드. 테스트가 캐시를 쓰지 않도록
 각 테스트 시작 시 lru_cache 클리어.
+
+Import path: 프로덕션 컨테이너 (/app cwd) 와 동일하게 무접두 스타일 사용
+(`from policy.loader` 등). 로컬 pytest 는 아래 sys.path 추가로 app/ 를 root 처리.
 """
 
 from __future__ import annotations
 
+import sys
 from pathlib import Path
 
+REPO_ROOT = Path(__file__).resolve().parent.parent.parent
+APP_DIR = REPO_ROOT / "app"
+if str(APP_DIR) not in sys.path:
+    sys.path.insert(0, str(APP_DIR))
+
 import pytest
 
-from app.policy import loader as policy_loader
-from app.policy import prompt_render
+from policy import loader as policy_loader
+from policy import prompt_render
 
 
-REPO_ROOT = Path(__file__).resolve().parent.parent.parent
 DEFAULT_YAML = REPO_ROOT / "domain_policy.yaml"
 
 

tests/policy/test_audit_patterns.py

@@ -9,7 +9,7 @@ from __future__ import annotations
 
 import pytest
 
-from app.policy.audit import check_4b_output_violations
+from policy.audit import check_4b_output_violations
 
 
 # =====================================================================

tests/policy/test_envelope_contract.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 
 import pytest
 
-from app.ai.envelope import EscalationEnvelope
+from ai.envelope import EscalationEnvelope
 
 
 def test_envelope_round_trip():

tests/policy/test_policy_loader_schema.py

@@ -6,8 +6,8 @@ import pytest
 import yaml
 from pydantic import ValidationError
 
-from app.policy import loader as policy_loader
-from app.policy.schema import DomainPolicy
+from policy import loader as policy_loader
+from policy.schema import DomainPolicy
 
 
 def test_default_yaml_loads(policy):

tests/policy/test_prompt_render.py

@@ -4,8 +4,8 @@ from __future__ import annotations
 
 import pytest
 
-from app.policy import prompt_render
-from app.policy.prompt_render import (
+from policy import prompt_render
+from policy.prompt_render import (
     KNOWN_4B_TASKS,
     KNOWN_26B_TASKS,
     policy_version,

tests/policy/test_routing_decisions.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 
 import pytest
 
-from app.policy.routing import (
+from policy.routing import (
     REASON_FALLBACK_DOMAIN,
     REASON_HIGH_IMPACT,
     REASON_LONG_CONTEXT,

tests/policy/test_self_declare_add_only.py

@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from app.policy.routing import decide_routing
+from policy.routing import decide_routing
 
 
 def test_deterministic_true_self_false_stays_high_impact(policy):

tests/policy/test_shadow_logger_inmem.py

@@ -4,8 +4,8 @@ from __future__ import annotations
 
 import pytest
 
-from app.policy.routing import RoutingDecision, decide_routing
-from app.policy.shadow import InMemoryShadowLogger, ShadowLogger
+from policy.routing import RoutingDecision, decide_routing
+from policy.shadow import InMemoryShadowLogger, ShadowLogger
 
 
 @pytest.fixture