BaseHTTPMiddleware (Starlette 0.50.0) uses anyio.create_task_group() internally,
creating separate asyncio tasks for dispatch vs call_next. ContextVars set in
dispatch() were not visible to outer middleware like log_requests.
Converting to raw ASGI middleware ensures trace_id is seeded in the root task
context, visible to ALL middleware layers.
Key changes:
- Replace BaseHTTPMiddleware with raw ASGI __call__(self, scope, receive, send)
- UUID v4 validation: check parsed.version == 4 explicitly instead of relying
on uuid.UUID(hex=..., version=4) which silently mutates non-v4 UUIDs
- Add @RATIONALE and @REJECTED tags per semantics-core protocol
- Update app.py comment to document the architectural decision
busya
ee5ebf08de