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/mixins/_transition.scss

@@ -0,0 +1,26 @@
+// stylelint-disable property-disallowed-list
+@mixin transition($transition...) {
+  @if length($transition) == 0 {
+    $transition: $transition-base;
+  }
+
+  @if length($transition) > 1 {
+    @each $value in $transition {
+      @if $value == null or $value == none {
+        @warn "The keyword 'none' or 'null' must be used as a single argument.";
+      }
+    }
+  }
+
+  @if $enable-transitions {
+    @if nth($transition, 1) != null {
+      transition: $transition;
+    }
+
+    @if $enable-reduced-motion and nth($transition, 1) != null and nth($transition, 1) != none {
+      @media (prefers-reduced-motion: reduce) {
+        transition: none;
+      }
+    }
+  }
+}