feat: The Other Dude v9.0.1 — full-featured email system

ci: add GitHub Pages deployment workflow for docs site

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/alembic/versions/021_system_tenant_for_audit.py

@@ -0,0 +1,44 @@
+"""Add system tenant for super_admin audit log entries.
+
+Revision ID: 021
+Revises: 020
+Create Date: 2026-03-04
+
+The super_admin has NULL tenant_id, but audit_logs.tenant_id has a FK
+to tenants and is NOT NULL.  Code was using uuid.UUID(int=0) as a
+substitute, but that row didn't exist — causing FK violations that
+silently dropped every super_admin audit entry.
+
+This migration inserts a sentinel 'System (Internal)' tenant so
+audit_logs can reference it.
+"""
+
+from alembic import op
+
+revision = "021"
+down_revision = "020"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.execute(
+        """
+        INSERT INTO tenants (id, name, description)
+        VALUES (
+            '00000000-0000-0000-0000-000000000000',
+            'System (Internal)',
+            'Internal tenant for super_admin audit entries'
+        )
+        ON CONFLICT (id) DO NOTHING
+        """
+    )
+
+
+def downgrade() -> None:
+    op.execute(
+        """
+        DELETE FROM tenants
+        WHERE id = '00000000-0000-0000-0000-000000000000'
+        """
+    )