feat(ui): Velocity redesign — foundations (tokens, theme, chrome)

Re-skin the app into the "Velocity" neo-brutalist direction: acid-lime
accent, hard offset shadows, slammed uppercase headlines, rounded
brutalist blocks. Light "paper" chassis + a warm-charcoal dark mode, both
keeping the lime accent and a constant black appbar; the light/dark toggle
is preserved.

- Type is Cyrillic-complete (the mockup's Anton/DM Sans/Space Mono are not,
  and this product is Russian-first): Oswald (display) + Manrope (body) +
  JetBrains Mono (numerals), loaded via the existing Google Fonts CDN.
- app.css: Velocity token palette (light+dark) + brutalist shared
  components (cards, kicker chips, stat blocks, nav, segmented, sections,
  anomaly badge); diagonal-hatch texture; electric-blue focus rings.
- MarathonTheme + Tokens.cs: Mud palette / typography / radius retargeted
  so every Mud component follows; appbar black, drawer flipped to paper.
- MainLayout + NavBody chrome: black appbar, lime capture chip, paper
  drawer with brutalist nav blocks (fixes the old white-on-paper brand).
- OddsTimeline + SportIcon recoloured to the Velocity palette (chart lines
  now read on both themes; dropped the off-brand purple sport hue).

Foundations only — build clean, all 568 tests green. Page-level polish
(Results winner colours, bespoke page styles) rolls out next.

src/Marathon.UI/Components/SportIcon.razor

@@ -20,10 +20,10 @@
         flex: 0 0 auto;
     }
     .m-sport svg { width: 100%; height: 100%; display: block; }
-    .m-sport[data-sport="6"] { color: #d97706; }
-    .m-sport[data-sport="11"] { color: #15803d; }
-    .m-sport[data-sport="22723"] { color: #0369a1; }
-    .m-sport[data-sport="43658"] { color: #6d28d9; }
+    .m-sport[data-sport="6"] { color: #ff8a00; }      /* basketball — amber */
+    .m-sport[data-sport="11"] { color: #1f9e3d; }     /* football — green */
+    .m-sport[data-sport="22723"] { color: #0d9488; }  /* tennis — teal */
+    .m-sport[data-sport="43658"] { color: #244bff; }  /* hockey — electric blue */
     [data-theme="dark"] .m-sport { filter: brightness(1.1); }
 </style>