Eliminate Python dependency: embed frontend assets in odoo-go

- Copy all OWL frontend assets (JS/CSS/XML/fonts/images) into frontend/
  directory (2925 files, 43MB) — no more runtime reads from Python Odoo
- Replace OdooAddonsPath config with FrontendDir pointing to local frontend/
- Rewire bundle.go, static.go, templates.go, webclient.go to read from
  frontend/ instead of external Python Odoo addons directory
- Auto-detect frontend/ and build/ dirs relative to binary in main.go
- Delete obsolete Python helper scripts (tools/*.py)

The Go server is now fully self-contained: single binary + frontend/ folder.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/sale/static/src/interactions/sale_sidebar.js

@@ -0,0 +1,26 @@
+import { Sidebar } from "@portal/interactions/sidebar";
+import { registry } from "@web/core/registry";
+
+export class SaleSidebar extends Sidebar {
+    static selector = ".o_portal_sale_sidebar";
+
+    setup() {
+        super.setup();
+        this.spyWatched = document.querySelector("body[data-target='.navspy']");
+    }
+
+    start() {
+        super.start();
+        // Nav Menu ScrollSpy
+        this.generateMenu();
+        // After signature, automatically open the popup for payment
+        const searchParams = new URLSearchParams(window.location.search.substring(1));
+        if (searchParams.get("allow_payment") === "yes") {
+            this.el.querySelector("#o_sale_portal_paynow")?.click();
+        }
+    }
+}
+
+registry
+    .category("public.interactions")
+    .add("sale.sale_sidebar", SaleSidebar);