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/web/static/lib/bootstrap/scss/_transitions.scss

@@ -0,0 +1,27 @@
+.fade {
+  @include transition($transition-fade);
+
+  &:not(.show) {
+    opacity: 0;
+  }
+}
+
+// scss-docs-start collapse-classes
+.collapse {
+  &:not(.show) {
+    display: none;
+  }
+}
+
+.collapsing {
+  height: 0;
+  overflow: hidden;
+  @include transition($transition-collapse);
+
+  &.collapse-horizontal {
+    width: 0;
+    height: auto;
+    @include transition($transition-collapse-width);
+  }
+}
+// scss-docs-end collapse-classes