fix(migrations): restore accidentally deleted migration files 038-042

Migration files 038-042 were accidentally deleted by commit d2217531
("Sentinel: Fix SSRF in IMAP connections"), which broke container
startup because existing databases had alembic_version stamped to
042_add_file_shares — a revision Alembic could no longer find.

Restored from the parent of that commit:
- 038_add_api_token_expires_at.py
- 039_add_classification_rules.py
- 040_add_automation_hooks.py
- 041_add_document_comments_and_annotations.py
- 042_add_file_shares.py

Alembic now resolves a clean single-head chain (001→042).

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>
Agent-Logs-Url: https://github.com/christianlouis/DocuElevate/sessions/f6165a49-2ec0-4158-9f1f-d508bb0489fe

migrations/versions/039_add_classification_rules.py

@@ -0,0 +1,46 @@
+"""Add classification_rules table for custom document classification rules.
+
+Revision ID: 039_add_classification_rules
+Revises: 038_add_api_token_expires_at
+Create Date: 2026-03-17
+"""
+
+from typing import Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "039_add_classification_rules"
+down_revision: Union[str, None] = "038_add_api_token_expires_at"
+depends_on: Union[str, None] = None
+
+
+def upgrade() -> None:
+    """Create classification_rules table."""
+    op.create_table(
+        "classification_rules",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("owner_id", sa.String(), nullable=True),
+        sa.Column("name", sa.String(255), nullable=False),
+        sa.Column("category", sa.String(100), nullable=False),
+        sa.Column("rule_type", sa.String(50), nullable=False),
+        sa.Column("pattern", sa.String(1000), nullable=False),
+        sa.Column("priority", sa.Integer(), nullable=False, server_default="0"),
+        sa.Column("case_sensitive", sa.Boolean(), nullable=False, server_default="0"),
+        sa.Column("enabled", sa.Boolean(), nullable=False, server_default="1"),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now()),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now()),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("owner_id", "name", name="uq_classification_rules_owner_name"),
+    )
+    op.create_index("ix_classification_rules_id", "classification_rules", ["id"])
+    op.create_index("ix_classification_rules_owner_id", "classification_rules", ["owner_id"])
+    op.create_index("ix_classification_rules_category", "classification_rules", ["category"])
+
+
+def downgrade() -> None:
+    """Drop classification_rules table."""
+    op.drop_index("ix_classification_rules_category", "classification_rules")
+    op.drop_index("ix_classification_rules_owner_id", "classification_rules")
+    op.drop_index("ix_classification_rules_id", "classification_rules")
+    op.drop_table("classification_rules")