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/purchase/static/src/interactions/purchase_datetimepicker.js

@@ -0,0 +1,34 @@
+import { Interaction } from "@web/public/interaction";
+import { registry } from "@web/core/registry";
+
+import { rpc } from "@web/core/network/rpc";
+
+export class PurchaseDatetimePicker extends Interaction {
+    static selector = ".o-purchase-datetimepicker";
+
+    start() {
+        this.registerCleanup(
+            this.services.datetime_picker
+                .create({
+                    target: this.el,
+                    onChange: (newDate) => {
+                        const { accessToken, orderId, lineId } = this.el.dataset;
+                        this.waitFor(
+                            rpc(`/my/purchase/${orderId}/update?access_token=${accessToken}`, {
+                                [lineId]: newDate.toISODate(),
+                            })
+                        );
+                    },
+                    pickerProps: {
+                        type: "date",
+                        value: luxon.DateTime.fromISO(this.el.dataset.value),
+                    },
+                })
+                .enable()
+        );
+    }
+}
+
+registry
+    .category("public.interactions")
+    .add("purchase.purchase_datetime_picker", PurchaseDatetimePicker);

frontend/purchase/static/src/interactions/purchase_sidebar.js

@@ -0,0 +1,21 @@
+import { Sidebar } from "@portal/interactions/sidebar";
+import { registry } from "@web/core/registry";
+
+export class PurchaseSidebar extends Sidebar {
+    static selector = ".o_portal_purchase_sidebar";
+
+    setup() {
+        super.setup();
+        this.spyWatched = document.querySelector("body[data-target='.navspy']");
+    }
+
+    start() {
+        super.start();
+        // Nav Menu ScrollSpy
+        this.generateMenu({ "max-width": "200px" });
+    }
+}
+
+registry
+    .category("public.interactions")
+    .add("purchase.purchase_sidebar", PurchaseSidebar);