chore: consolidate to single ruff config in root pyproject.toml

- Merge web ruff settings (select E/F/I/UP, line-length 100) into root config
- Remove [tool.ruff] section from web/pyproject.toml
- Remove "web" from root ruff exclude list
- Simplify pre-commit hook to one command: ruff check .
- Update CI to use: uv run ruff check . (from repo root)

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

web/tests/test_billing_helpers.py

@@ -14,9 +14,7 @@ from beanflows.billing.routes import (
     upsert_subscription,
 )
 from beanflows.core import config
-from hypothesis import HealthCheck, given
-from hypothesis import settings as h_settings
-from hypothesis import strategies as st
+from hypothesis import HealthCheck, given, settings as h_settings, strategies as st
 
 # ════════════════════════════════════════════════════════════
 # get_subscription