Webmention improvements

- Tweak design for IndieAuth login flow
 - Webmentions notifications support
 - Refactor webmentions processing

alembic/versions/2b51ae7047cb_webmention_notifications.py

@@ -0,0 +1,32 @@
+"""Webmention notifications
+
+Revision ID: 2b51ae7047cb
+Revises: e58c1ffadf2e
+Create Date: 2022-07-19 20:22:06.968951
+
+"""
+import sqlalchemy as sa
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = '2b51ae7047cb'
+down_revision = 'e58c1ffadf2e'
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('notifications', schema=None) as batch_op:
+        batch_op.create_foreign_key('fk_webmention_id', 'webmention', ['webmention_id'], ['id'])
+
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('notifications', schema=None) as batch_op:
+        batch_op.drop_constraint('fk_webmention_id', type_='foreignkey')
+
+    # ### end Alembic commands ###