feat: per-host WinRM/SSH credentials override (0.5.17)

Allow host-level login/password for home/workgroup PCs while keeping global domain admins in Settings.

backend/alembic/versions/027_host_mgmt_credentials.py

@@ -0,0 +1,25 @@
+"""per-host management credentials (SSH / WinRM override)
+
+Revision ID: 027_host_mgmt_credentials
+Revises: 026_host_silence_dedupe
+Create Date: 2026-07-14
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+revision = "027_host_mgmt_credentials"
+down_revision = "026_host_silence_dedupe"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column("hosts", sa.Column("mgmt_user", sa.String(length=256), nullable=True))
+    op.add_column("hosts", sa.Column("mgmt_password", sa.Text(), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("hosts", "mgmt_password")
+    op.drop_column("hosts", "mgmt_user")