docs: enhance AGENTS.md files with Go linting, DI patterns, barrel re-export, TS best practices [guardrail-change]

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

AGENTS.python.md

@@ -78,6 +78,57 @@ async def create_dsr_request(
 - `pip-audit` in CI.
 - Async-first: prefer `httpx.AsyncClient`, `asyncpg`/`SQLAlchemy 2.x async`.
 
+## mypy configuration
+
+`backend-compliance/mypy.ini` is the mypy config. Strict mode is on globally; per-module overrides exist only for legacy files that have not been cleaned up yet.
+
+- New modules added to `compliance/services/` or `compliance/repositories/` **must** pass `mypy --strict`.
+- To type-check a new module: `cd backend-compliance && mypy compliance/your_new_module.py`
+- When you fully type a legacy file, **remove its loose-override block** from `mypy.ini` as part of the same PR.
+
+## Dependency injection
+
+Services and repositories are wired via FastAPI `Depends`. Never instantiate a service or repository directly inside a handler.
+
+```python
+# dependencies.py
+def get_my_service(db: AsyncSession = Depends(get_db)) -> MyService:
+    return MyService(MyRepository(db))
+
+# router
+@router.get("/items", response_model=list[ItemRead])
+async def list_items(svc: MyService = Depends(get_my_service)) -> list[ItemRead]:
+    return await svc.list()
+```
+
+- Services take repositories in `__init__`; repositories take `Session` or `AsyncSession`.
+
+## Structured logging
+
+```python
+import structlog
+logger = structlog.get_logger()
+
+# Always bind context before logging:
+logger.bind(tenant_id=str(tid), action="create_dsfa").info("dsfa created")
+```
+
+- Audit-relevant actions must use the audit logger with a `legal_basis` field.
+- Never log secrets, PII, or full request bodies.
+
+## Barrel re-export pattern
+
+When an oversized file (e.g. `schemas.py`, `models.py`) is split into a sub-package, the original stays as a **thin re-exporter** so existing consumer imports keep working:
+
+```python
+# compliance/schemas.py  (barrel — DO NOT ADD NEW CODE HERE)
+from .schemas.ai import *        # noqa: F401, F403
+from .schemas.consent import *   # noqa: F401, F403
+```
+
+- New code imports from the specific module (e.g. `from compliance.schemas.ai import AIRiskRead`), not the barrel.
+- `from module import *` is only permitted in barrel files.
+
 ## Errors & logging
 
 - Domain errors inherit from a single `DomainError` base per service.
@@ -91,4 +142,7 @@ async def create_dsr_request(
 - Change a public route's path/method/status/schema without simultaneous dashboard fix.
 - Catch `Exception` broadly — catch the specific domain or library error.
 - Put business logic in a router or in a Pydantic validator.
+- `from module import *` in new code — only in barrel re-exporters.
+- `raise HTTPException` inside the service layer — raise domain exceptions; map them in the router.
+- Use `model_validate` on untrusted external data without an explicit schema boundary.
 - Create a new file >500 lines. Period.