fix(css): serve live theme CSS verbatim instead of diverging SCSS fork

The Sass file in sass/_praxis_theme.scss had drifted from the live
_style.css over the project's life — different line-heights (34/28 vs
24), padding overrides, restructured selectors, and a few sections that
the SCSS parser couldn't accept anyway (CSS // line-comments, missing
semicolons inherited from the original hand-written CSS).

For Phase 1 visual parity the correct source of truth is the live CSS,
not a re-edited copy. Drop compile_sass, ship the live _style.css as
/css/praxis.css straight from static/, and point base.html at it. This
restores the live vertical rhythm (paragraph spacing, banner padding)
that had been subtly off.

config.toml

@@ -2,7 +2,7 @@ base_url = "https://preview.praxis-am-lienhardplatz.de"
 title = "Praxis am Lienhardplatz"
 description = "Dr. Oliver Riemann, Dr. Angela Krey und Christian Malyga begrüßen Sie in der Hausärztlichen Gemeinschaftspraxis am Lienhardplatz in Wuppertal-Vohwinkel"
 default_language = "de"
-compile_sass = true
+compile_sass = false
 build_search_index = false
 generate_feeds = false