correcting nullable=False which is causing unit test issues

Author: Vishakh Pillai

src/webapp/database.py

@@ -358,7 +358,9 @@ class FileTable(Base):
     source: Mapped[str | None] = mapped_column(String(VAR_CHAR_LENGTH), nullable=True)
     # The schema type(s) of this file.
     schemas: Mapped[list[str]] = mapped_column(
-        MutableList.as_mutable((JSON())), nullable=False
+        MutableList.as_mutable((JSON())),
+        nullable=False,
+        default=list,
     )
     # If null, the following is non-deleted.
     # The deleted field indicates whether there is a pending deletion request on the data.
@@ -371,9 +373,9 @@ class FileTable(Base):
     )
     retention_days: Mapped[int] = mapped_column(nullable=True)
     # Whether the file was generated by SST. (e.g. was it input or output)
-    sst_generated: Mapped[bool] = mapped_column(nullable=False)
+    sst_generated: Mapped[bool] = mapped_column(nullable=False, default=False)
     # Whether the file was approved (in the case of output) or valid for input.
-    valid: Mapped[bool] = mapped_column(nullable=False)
+    valid: Mapped[bool] = mapped_column(nullable=False, default=False)
     created_at: Mapped[datetime.datetime] = mapped_column(
         DateTime(timezone=True), server_default=func.now()
     )