feat(subscriptions): migrate subscription management to merchant level and seed tiers

Move subscription create/edit from store detail (broken endpoint) to merchant
detail page with proper modal UI. Seed 4 subscription tiers (Essential,
Professional, Business, Enterprise) in init_production.py. Also includes
cross-module dependency declarations, store domain platform_id migration,
platform context middleware, CMS route fixes, and migration backups.

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

alembic/versions_backup/za0k1l2m3n4o5_add_admin_menu_config.py

@@ -0,0 +1,128 @@
+"""Add admin menu configuration table
+
+Revision ID: za0k1l2m3n4o5
+Revises: z9j0k1l2m3n4
+Create Date: 2026-01-25
+
+Adds configurable admin sidebar menus:
+- Platform-level config: Controls which menu items platform admins see
+- User-level config: Controls which menu items super admins see
+- Opt-out model: All items visible by default
+- Mandatory items enforced at application level (companies, vendors, users, settings)
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "za0k1l2m3n4o5"
+down_revision = "z9j0k1l2m3n4"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # Create admin_menu_configs table
+    op.create_table(
+        "admin_menu_configs",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column(
+            "platform_id",
+            sa.Integer(),
+            nullable=True,
+            comment="Platform scope - applies to all platform admins of this platform",
+        ),
+        sa.Column(
+            "user_id",
+            sa.Integer(),
+            nullable=True,
+            comment="User scope - applies to this specific super admin",
+        ),
+        sa.Column(
+            "menu_item_id",
+            sa.String(50),
+            nullable=False,
+            comment="Menu item identifier from registry (e.g., 'products', 'inventory')",
+        ),
+        sa.Column(
+            "is_visible",
+            sa.Boolean(),
+            nullable=False,
+            server_default="true",
+            comment="Whether this menu item is visible (False = hidden)",
+        ),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            nullable=False,
+            server_default=sa.func.now(),
+        ),
+        sa.Column(
+            "updated_at",
+            sa.DateTime(timezone=True),
+            nullable=False,
+            server_default=sa.func.now(),
+            onupdate=sa.func.now(),
+        ),
+        # Foreign keys
+        sa.ForeignKeyConstraint(
+            ["platform_id"],
+            ["platforms.id"],
+            ondelete="CASCADE",
+        ),
+        sa.ForeignKeyConstraint(
+            ["user_id"],
+            ["users.id"],
+            ondelete="CASCADE",
+        ),
+        sa.PrimaryKeyConstraint("id"),
+        # Unique constraints
+        sa.UniqueConstraint("platform_id", "menu_item_id", name="uq_platform_menu_config"),
+        sa.UniqueConstraint("user_id", "menu_item_id", name="uq_user_menu_config"),
+        # Check constraint: exactly one scope must be set
+        sa.CheckConstraint(
+            "(platform_id IS NOT NULL AND user_id IS NULL) OR "
+            "(platform_id IS NULL AND user_id IS NOT NULL)",
+            name="ck_admin_menu_config_scope",
+        ),
+    )
+
+    # Create indexes for performance
+    op.create_index(
+        "idx_admin_menu_configs_platform_id",
+        "admin_menu_configs",
+        ["platform_id"],
+    )
+    op.create_index(
+        "idx_admin_menu_configs_user_id",
+        "admin_menu_configs",
+        ["user_id"],
+    )
+    op.create_index(
+        "idx_admin_menu_configs_menu_item_id",
+        "admin_menu_configs",
+        ["menu_item_id"],
+    )
+    op.create_index(
+        "idx_admin_menu_config_platform_visible",
+        "admin_menu_configs",
+        ["platform_id", "is_visible"],
+    )
+    op.create_index(
+        "idx_admin_menu_config_user_visible",
+        "admin_menu_configs",
+        ["user_id", "is_visible"],
+    )
+
+
+def downgrade() -> None:
+    # Drop indexes
+    op.drop_index("idx_admin_menu_config_user_visible", table_name="admin_menu_configs")
+    op.drop_index("idx_admin_menu_config_platform_visible", table_name="admin_menu_configs")
+    op.drop_index("idx_admin_menu_configs_menu_item_id", table_name="admin_menu_configs")
+    op.drop_index("idx_admin_menu_configs_user_id", table_name="admin_menu_configs")
+    op.drop_index("idx_admin_menu_configs_platform_id", table_name="admin_menu_configs")
+
+    # Drop table
+    op.drop_table("admin_menu_configs")