feat: initial shared library extraction

Contains shared infrastructure for all coop services:
- shared/ (factory, urls, user_loader, context, internal_api, jinja_setup)
- models/ (User, Order, Calendar, Ticket, Product, Ghost CMS)
- db/ (SQLAlchemy async session, base)
- suma_browser/app/ (csrf, middleware, errors, authz, redis_cacher, payments, filters, utils)
- suma_browser/templates/ (shared base layouts, macros, error pages)
- static/ (CSS, JS, fonts, images)
- alembic/ (database migrations)
- config/ (app-config.yaml)
- editor/ (Lexical editor Node.js build)
- requirements.txt

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

alembic/versions/0006_update_calendar_entries.py

@@ -0,0 +1,28 @@
+from alembic import op
+import sqlalchemy as sa
+
+revision = '0006_update_calendar_entries'
+down_revision = '0005_add_description'  # use the appropriate previous revision ID
+branch_labels = None
+depends_on = None
+
+def upgrade():
+    # Add user_id and session_id columns
+    op.add_column('calendar_entries', sa.Column('user_id', sa.Integer(), nullable=True))
+    op.create_foreign_key('fk_calendar_entries_user_id', 'calendar_entries', 'users', ['user_id'], ['id'])
+    op.add_column('calendar_entries', sa.Column('session_id', sa.String(length=128), nullable=True))
+    # Add state and cost columns
+    op.add_column('calendar_entries', sa.Column('state', sa.String(length=20), nullable=False, server_default='pending'))
+    op.add_column('calendar_entries', sa.Column('cost', sa.Numeric(10,2), nullable=False, server_default='10'))
+    # (Optional) Create indexes on the new columns
+    op.create_index('ix_calendar_entries_user_id', 'calendar_entries', ['user_id'])
+    op.create_index('ix_calendar_entries_session_id', 'calendar_entries', ['session_id'])
+
+def downgrade():
+    op.drop_index('ix_calendar_entries_session_id', table_name='calendar_entries')
+    op.drop_index('ix_calendar_entries_user_id', table_name='calendar_entries')
+    op.drop_column('calendar_entries', 'cost')
+    op.drop_column('calendar_entries', 'state')
+    op.drop_column('calendar_entries', 'session_id')
+    op.drop_constraint('fk_calendar_entries_user_id', 'calendar_entries', type_='foreignkey')
+    op.drop_column('calendar_entries', 'user_id')