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/odoo/base/static/src/css/modules.css

@@ -0,0 +1,30 @@
+.oe_module_flag {
+    position: absolute;
+    left: 12px;
+    top: calc(50% - 35px);
+    font: 27px icon;
+    text-shadow: 0px 0px 5px rgba(0, 0, 0, 0.5);
+}
+
+.o_kanban_view.o_modules_kanban .o_kanban_renderer .o_kanban_record .o_dropdown_kanban,
+.o_modules_field .o_modules_kanban .o_kanban_renderer .o_kanban_record .o_dropdown_kanban {
+    visibility: visible;
+    opacity: 0.5;
+}
+
+.o_kanban_view.o_modules_kanban .o_kanban_renderer .o_kanban_record:hover .o_dropdown_kanban,
+.o_kanban_view.o_modules_kanban .o_kanban_renderer .o_kanban_record .o_dropdown_kanban.show {
+    opacity: 1;
+}
+
+.o_modules_field .o_modules_kanban .o_kanban_renderer {
+    --KanbanRecord-width: 280px;
+    --KanbanRecord-width-small: 280px;
+}
+
+.o_module_form.o_form_view .oe_avatar > img {
+    border: none;
+    box-shadow: none;
+    max-width: 70px;
+    max-height: 70px;
+}