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/0007_add_oid_entries.py

@@ -0,0 +1,50 @@
+from alembic import op
+import sqlalchemy as sa
+
+revision = "0007_add_oid_entries"
+down_revision = "0006_update_calendar_entries"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Add order_id column
+    op.add_column(
+        "calendar_entries",
+        sa.Column("order_id", sa.Integer(), nullable=True),
+    )
+    op.create_foreign_key(
+        "fk_calendar_entries_order_id",
+        "calendar_entries",
+        "orders",
+        ["order_id"],
+        ["id"],
+        ondelete="SET NULL",
+    )
+    op.create_index(
+        "ix_calendar_entries_order_id",
+        "calendar_entries",
+        ["order_id"],
+        unique=False,
+    )
+
+    # Optional: add an index on state if you want faster queries by state
+    op.create_index(
+        "ix_calendar_entries_state",
+        "calendar_entries",
+        ["state"],
+        unique=False,
+    )
+
+
+def downgrade():
+    # Drop indexes and FK in reverse order
+    op.drop_index("ix_calendar_entries_state", table_name="calendar_entries")
+
+    op.drop_index("ix_calendar_entries_order_id", table_name="calendar_entries")
+    op.drop_constraint(
+        "fk_calendar_entries_order_id",
+        "calendar_entries",
+        type_="foreignkey",
+    )
+    op.drop_column("calendar_entries", "order_id")