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/tests/mock_server/mock_models/sale_order.js

@@ -0,0 +1,14 @@
+import { models } from "@web/../tests/web_test_helpers";
+
+
+export class SaleOrder extends models.ServerModel {
+    _name = "sale.order";
+
+    _records = [
+        {
+            id: 1,
+            name: "first record",
+            order_line: [],
+        },
+    ];
+}

frontend/sale/static/tests/mock_server/mock_models/sale_order_line.js

@@ -0,0 +1,9 @@
+import { fields, models } from "@web/../tests/web_test_helpers";
+
+
+export class SaleOrderLine extends models.ServerModel {
+    _name = "sale.order.line";
+
+    // Store the field for testing to be able to set the translation at the record creation.
+    translated_product_name = fields.Char({store: true});
+}