feat(integration): add docs/visio logos, theme.css, and nginx updates

Add SVG logos for docs and visio apps. Update drive, mail, people logos.
Add theme.css served at /api/v2/theme.css for La Suite frontend theming.
Update nginx to serve theme endpoint and tighten cache headers.
Update Dockerfile to include new static assets.

theme.css

@@ -0,0 +1,40 @@
+/*
+ * O Estúdio — runtime brand overrides for docs + people.
+ * Loaded after the compiled Cunningham CSS via nginx sub_filter injection.
+ * Overrides :root CSS variables — no app rebuild required.
+ */
+
+:root {
+  /* Font */
+  --c--globals--font--families--base: 'Ysabeau Variable', Inter, sans-serif;
+  --c--globals--font--families--accent: 'Ysabeau Variable', Inter, sans-serif;
+
+  /* Brand — amber/gold palette (replaces default blue/purple) */
+  --c--globals--colors--brand-050: #fffbeb;
+  --c--globals--colors--brand-100: #fef3c7;
+  --c--globals--colors--brand-150: #fde9a0;
+  --c--globals--colors--brand-200: #fde68a;
+  --c--globals--colors--brand-250: #fde047;
+  --c--globals--colors--brand-300: #fcd34d;
+  --c--globals--colors--brand-350: #fbcf3f;
+  --c--globals--colors--brand-400: #fbbf24;
+  --c--globals--colors--brand-450: #f8b31a;
+  --c--globals--colors--brand-500: #f59e0b;
+  --c--globals--colors--brand-550: #e8920a;
+  --c--globals--colors--brand-600: #d97706;
+  --c--globals--colors--brand-650: #c26d05;
+  --c--globals--colors--brand-700: #b45309;
+  --c--globals--colors--brand-750: #9a4508;
+  --c--globals--colors--brand-800: #92400e;
+  --c--globals--colors--brand-850: #7c370c;
+  --c--globals--colors--brand-900: #78350f;
+  --c--globals--colors--brand-950: #451a03;
+
+  /* Logo gradient colours used by ui-kit header components */
+  --c--globals--colors--logo-1: #f59e0b;
+  --c--globals--colors--logo-2: #d97706;
+  --c--globals--colors--logo-1-light: #f59e0b;
+  --c--globals--colors--logo-2-light: #d97706;
+  --c--globals--colors--logo-1-dark: #fcd34d;
+  --c--globals--colors--logo-2-dark: #fbbf24;
+}