refactor: remove UserSearchSpacePreference model and related relationships

- Deleted UserSearchSpacePreference class and its relationships from SearchSpace and User models.
- Cleaned up unused code to streamline database interactions.

surfsense_backend/alembic/versions/42_drop_user_search_space_preferences.py

@@ -0,0 +1,41 @@
+"""Drop user_search_space_preferences table
+
+Revision ID: 42
+Revises: 41
+Create Date: 2025-11-28
+
+This table is no longer needed after RBAC implementation:
+- LLM preferences are now stored on SearchSpace directly
+- User-SearchSpace relationships are handled by SearchSpaceMembership
+"""
+
+import sqlalchemy as sa
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "42"
+down_revision = "41"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Drop the user_search_space_preferences table
+    op.drop_table("user_search_space_preferences")
+
+
+def downgrade():
+    # Recreate the table if rolling back
+    op.create_table(
+        "user_search_space_preferences",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now()),
+        sa.Column("user_id", sa.UUID(), sa.ForeignKey("user.id", ondelete="CASCADE"), nullable=False),
+        sa.Column("search_space_id", sa.Integer(), sa.ForeignKey("searchspaces.id", ondelete="CASCADE"), nullable=False),
+        sa.Column("long_context_llm_id", sa.Integer(), nullable=True),
+        sa.Column("fast_llm_id", sa.Integer(), nullable=True),
+        sa.Column("strategic_llm_id", sa.Integer(), nullable=True),
+        sa.UniqueConstraint("user_id", "search_space_id", name="uq_user_searchspace"),
+    )
+

surfsense_backend/app/db.py

@@ -441,11 +441,6 @@ class SearchSpace(BaseModel, TimestampMixin):
         order_by="LLMConfig.id",
         cascade="all, delete-orphan",
     )
-    user_preferences = relationship(
-        "UserSearchSpacePreference",
-        back_populates="search_space",
-        cascade="all, delete-orphan",
-    )
 
     # RBAC relationships
     roles = relationship(
@@ -527,36 +522,6 @@ class LLMConfig(BaseModel, TimestampMixin):
     search_space = relationship("SearchSpace", back_populates="llm_configs")
 
 
-class UserSearchSpacePreference(BaseModel, TimestampMixin):
-    __tablename__ = "user_search_space_preferences"
-    __table_args__ = (
-        UniqueConstraint(
-            "user_id",
-            "search_space_id",
-            name="uq_user_searchspace",
-        ),
-    )
-
-    user_id = Column(
-        UUID(as_uuid=True), ForeignKey("user.id", ondelete="CASCADE"), nullable=False
-    )
-    search_space_id = Column(
-        Integer, ForeignKey("searchspaces.id", ondelete="CASCADE"), nullable=False
-    )
-
-    # User-specific LLM preferences for this search space
-    # Note: These can be negative IDs for global configs (from YAML) or positive IDs for custom configs (from DB)
-    # Foreign keys removed to support global configs with negative IDs
-    long_context_llm_id = Column(Integer, nullable=True)
-    fast_llm_id = Column(Integer, nullable=True)
-    strategic_llm_id = Column(Integer, nullable=True)
-
-    # Future RBAC fields can be added here
-    # role = Column(String(50), nullable=True)  # e.g., 'owner', 'editor', 'viewer'
-    # permissions = Column(JSON, nullable=True)
-
-    user = relationship("User", back_populates="search_space_preferences")
-    search_space = relationship("SearchSpace", back_populates="user_preferences")
 
 
 class Log(BaseModel, TimestampMixin):
@@ -720,11 +685,6 @@ if config.AUTH_TYPE == "GOOGLE":
             "OAuthAccount", lazy="joined"
         )
         search_spaces = relationship("SearchSpace", back_populates="user")
-        search_space_preferences = relationship(
-            "UserSearchSpacePreference",
-            back_populates="user",
-            cascade="all, delete-orphan",
-        )
 
         # RBAC relationships
         search_space_memberships = relationship(
@@ -746,11 +706,6 @@ else:
 
     class User(SQLAlchemyBaseUserTableUUID, Base):
         search_spaces = relationship("SearchSpace", back_populates="user")
-        search_space_preferences = relationship(
-            "UserSearchSpacePreference",
-            back_populates="user",
-            cascade="all, delete-orphan",
-        )
 
         # RBAC relationships
         search_space_memberships = relationship(