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/stock/static/tests/tours/tour_helper.js

@@ -0,0 +1,9 @@
+export function fail(errorMessage) {
+    throw new Error(errorMessage);
+}
+
+export function assert(current, expected, info) {
+    if (current !== expected) {
+        fail(`${info}: "${current}" instead of "${expected}".`);
+    }
+}