fix: only set BASIC_MEMORY_ENV=test during pytest runs

The alembic/env.py module was unconditionally setting BASIC_MEMORY_ENV='test'
at import time, which caused config.is_test_env to always return True. This
prevented the MCP server from starting the file watch service, breaking file
sync for external changes.

Fix: Only set the env var when PYTEST_CURRENT_TEST is set, indicating an
actual pytest run. This preserves test behavior while enabling watch service
in production.

Fixes #481

Co-authored-by: Paul Hernandez <phernandez@users.noreply.github.com>
Signed-off-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

Author: github-actions[bot]

src/basic_memory/alembic/env.py

@@ -21,8 +21,12 @@
 
 from basic_memory.config import ConfigManager
 
-# set config.env to "test" for pytest to prevent logging to file in utils.setup_logging()
-os.environ["BASIC_MEMORY_ENV"] = "test"
+# Trigger: only set test env when actually running under pytest
+# Why: alembic/env.py is imported during normal operations (MCP server startup, migrations)
+#      but we only want test behavior during actual test runs
+# Outcome: prevents is_test_env from returning True in production, enabling watch service
+if os.getenv("PYTEST_CURRENT_TEST") is not None:
+    os.environ["BASIC_MEMORY_ENV"] = "test"
 
 # Import after setting environment variable  # noqa: E402
 from basic_memory.models import Base  # noqa: E402