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/_grid.scss

@@ -0,0 +1,39 @@
+// Row
+//
+// Rows contain your columns.
+
+:root {
+  @each $name, $value in $grid-breakpoints {
+    --#{$prefix}breakpoint-#{$name}: #{$value};
+  }
+}
+
+@if $enable-grid-classes {
+  .row {
+    @include make-row();
+
+    > * {
+      @include make-col-ready();
+    }
+  }
+}
+
+@if $enable-cssgrid {
+  .grid {
+    display: grid;
+    grid-template-rows: repeat(var(--#{$prefix}rows, 1), 1fr);
+    grid-template-columns: repeat(var(--#{$prefix}columns, #{$grid-columns}), 1fr);
+    gap: var(--#{$prefix}gap, #{$grid-gutter-width});
+
+    @include make-cssgrid();
+  }
+}
+
+
+// Columns
+//
+// Common styles for small and large grid columns
+
+@if $enable-grid-classes {
+  @include make-grid-columns();
+}