feat: control-pipeline Service aus Compliance-Repo migriert

Control-Pipeline (Pass 0a/0b, BatchDedup, Generator) als eigenstaendiger
Service in Core, damit Compliance-Repo unabhaengig refakturiert werden kann.
Schreibt weiterhin ins compliance-Schema der shared PostgreSQL.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

control-pipeline/db/session.py

@@ -0,0 +1,37 @@
+"""Database session factory for control-pipeline.
+
+Connects to the shared PostgreSQL with search_path set to compliance schema.
+"""
+
+from sqlalchemy import create_engine, event
+from sqlalchemy.orm import sessionmaker
+
+from config import settings
+
+engine = create_engine(
+    settings.DATABASE_URL,
+    pool_pre_ping=True,
+    pool_size=5,
+    max_overflow=10,
+    echo=False,
+)
+
+
+@event.listens_for(engine, "connect")
+def set_search_path(dbapi_connection, connection_record):
+    cursor = dbapi_connection.cursor()
+    cursor.execute(f"SET search_path TO {settings.SCHEMA_SEARCH_PATH}")
+    cursor.close()
+    dbapi_connection.commit()
+
+
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+
+def get_db():
+    """FastAPI dependency for DB sessions."""
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()