feat: contact model restructure

Blank contacts are now generated on org creation and assigned to each contact type. These contacts are linked to the org, only accessible to the org, and removed when the org is removed.

With this all contact endpoints have been removed. Contact manipulation is done via the org only.

.alembic/versions/2026-05-25_contact_model_changes.py

@@ -0,0 +1,34 @@
+"""Contact model changes
+
+Revision ID: 8132c4b88665
+Revises: a147965e644e
+Create Date: 2026-05-25 13:09:22.635058
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = '8132c4b88665'
+down_revision: Union[str, Sequence[str], None] = 'a147965e644e'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('contact', sa.Column('org_id', sa.Integer(), nullable=False))
+    op.create_foreign_key(None, 'contact', 'organisation', ['org_id'], ['id'], ondelete='CASCADE')
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_constraint(None, 'contact', type_='foreignkey')
+    op.drop_column('contact', 'org_id')
+    # ### end Alembic commands ###