In-play win-probability timeline: the momentum curve on match pages

While a match runs, every poll records the in-play model probability
per game state (insert-if-new on minute+score) into inplay_history.
The match page draws it as a stacked area chart — home fills from the
bottom, away from the top, the gap is the draw — with minute ticks and
a 50% guide. Shows live (under the win-probability bar) and after full
time as its own card. EN/DE strings included.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/lib/i18n/de.ts

@@ -85,6 +85,7 @@ export const de: Dict = {
       saves: "Paraden",
     },
     timeline: "Spielverlauf",
+    momentum: "So schwankte die Siegwahrscheinlichkeit",
     preMatchModel: "Modell vor Anstoß",
     modelExpectation: "Modell-Prognose",
     expectedGoalsLine: "Erwartete Tore (xG): {home} – {away} · Modell-Wahrscheinlichkeiten, keine Wettempfehlung",