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>

editor/build.mjs

@@ -0,0 +1,45 @@
+import * as esbuild from "esbuild";
+import path from "path";
+import { fileURLToPath } from "url";
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const isProduction = process.env.NODE_ENV === "production";
+const isWatch = process.argv.includes("--watch");
+
+/** @type {import('esbuild').BuildOptions} */
+const opts = {
+  alias: {
+    "koenig-styles": path.resolve(
+      __dirname,
+      "node_modules/@tryghost/koenig-lexical/dist/index.css"
+    ),
+  },
+  entryPoints: ["src/index.jsx"],
+  bundle: true,
+  outdir: "../static/scripts",
+  entryNames: "editor",
+  format: "iife",
+  target: "es2020",
+  jsx: "automatic",
+  minify: isProduction,
+  define: {
+    "process.env.NODE_ENV": JSON.stringify(
+      isProduction ? "production" : "development"
+    ),
+  },
+  loader: {
+    ".svg": "dataurl",
+    ".woff": "file",
+    ".woff2": "file",
+    ".ttf": "file",
+  },
+  logLevel: "info",
+};
+
+if (isWatch) {
+  const ctx = await esbuild.context(opts);
+  await ctx.watch();
+  console.log("Watching for changes...");
+} else {
+  await esbuild.build(opts);
+}