docs: switch to sidebar-only navigation layout

Remove top navigation tabs in favor of left sidebar navigation with
right-side table of contents, matching the uv docs style.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 2 people

mkdocs.yml

@@ -35,8 +35,6 @@ theme:
     - navigation.instant.prefetch
     - navigation.instant.progress
     - navigation.tracking
-    - navigation.tabs
-    - navigation.tabs.sticky
     - navigation.indexes
     - navigation.sections
     - navigation.path