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>

server/src/db/db.ts

@@ -93,6 +93,18 @@ CREATE TABLE IF NOT EXISTS prediction_snapshots (
   market_json TEXT
 );
 
+CREATE TABLE IF NOT EXISTS inplay_history (
+  fixture_num INTEGER NOT NULL,
+  minute      INTEGER NOT NULL,
+  home_score  INTEGER NOT NULL,
+  away_score  INTEGER NOT NULL,
+  p_home      REAL NOT NULL,
+  p_draw      REAL NOT NULL,
+  p_away      REAL NOT NULL,
+  at          INTEGER NOT NULL,
+  PRIMARY KEY (fixture_num, minute, home_score, away_score)
+);
+
 CREATE TABLE IF NOT EXISTS ingest_log (
   id     INTEGER PRIMARY KEY AUTOINCREMENT,
   source TEXT NOT NULL,
@@ -135,6 +147,32 @@ export function cacheSet(key: string, value: string, ttl: number): void {
     .run(key, value, Date.now(), ttl);
 }
 
+// ---- in-play win-probability history (the momentum curve on match pages) ----
+export interface InplayPoint {
+  minute: number;
+  home_score: number;
+  away_score: number;
+  p_home: number;
+  p_draw: number;
+  p_away: number;
+}
+
+/** Insert-if-new keyed on (minute, score) — one point per game state. */
+export function recordInplay(num: number, p: InplayPoint): void {
+  db()
+    .prepare(`INSERT OR IGNORE INTO inplay_history
+      (fixture_num, minute, home_score, away_score, p_home, p_draw, p_away, at)
+      VALUES (?, ?, ?, ?, ?, ?, ?, ?)`)
+    .run(num, p.minute, p.home_score, p.away_score, p.p_home, p.p_draw, p.p_away, Date.now());
+}
+
+export function inplayHistory(num: number): InplayPoint[] {
+  return db()
+    .prepare(`SELECT minute, home_score, away_score, p_home, p_draw, p_away
+      FROM inplay_history WHERE fixture_num = ? ORDER BY minute, home_score + away_score`)
+    .all(num) as unknown as InplayPoint[];
+}
+
 /** Nightly consistent snapshot: VACUUM INTO a LOCAL temp file (SQLite needs
  *  real locking, which the CIFS-mounted archive cannot offer), then a plain
  *  sequential copy into the archive dir. Keeps the newest `keep` dated copies. */