4.0: integration and app compatibility

[lesnik512]

This was generated by AI during a pre-4.0 audit of main at 9cd88e7.

All 13 integrations were run against main (3.x baseline, then 4.0 main as a local wheel; pytest and ty).

Results

• aiogram, aiohttp, celery, fastapi, faststream, flask, grpc, litestar, pytest, starlette, taskiq, typer: all tests and ty pass on both 3.6 and 4.0 main. Only the pin needs widening.
• modern-di-arq: tests/test_lifespan.py:83 uses the removed ContainerClosedWarning (AttributeError, ty unresolved-attribute). Issue: Prepare for modern-di 4.0: rewrite test_restart_reopens_without_warning modern-di-arq#42
• fastapi-sqlalchemy-template and litestar-sqlalchemy-template: app/resources/db.py:46 uses request: Request | None = None; in 4.0 test_db_routing.py::test_no_request_uses_primary raises ContextValueNotSetError, the documented change. Issues: Prepare for modern-di 4.0: optional request parameter in db routing fastapi-sqlalchemy-template#77, Prepare for modern-di 4.0: optional request parameter in db routing litestar-sqlalchemy-template#56
• chat-app: no break; pin bumps only.
• No regressions: every failure is a documented 4.0 change.

Checklist (after the 4.0 code issues land, re-run the compat check first)

• modern-di-grpc: replace container.providers_registry.find_provider with container.find_provider (added in feat!: tighten Container's public surface (#565) #592) at modern_di_grpc/main.py:45 and tests/test_inject.py:191.
• Widen modern-di>=3,<4 to <5 and release: aiogram, aiohttp, arq, celery, fastapi, faststream, flask, grpc, litestar, pytest, starlette, taskiq, typer.
• modern-di-taskiq: docs/adr/0002-only-worker-lifecycle-is-wired.md:12 mentions ContainerClosedWarning (prose).
• Test helpers with X | None = None creator params in aiogram (dependencies.py:17), flask (:17), grpc (:26), taskiq (:17): comments describe 3.x optional semantics; reword.
• Templates and chat-app: bump integration pins after the integration releases.