feat(today): focus du jour — le rituel des 3 cartes (issue #5)

Table today_picks; POST /api/today/pin (max 3, idempotent) et
/unpin; page /today (picks en direct, candidates de l'encours,
reprises d'hier, récap du jour depuis le journal); bouton 📌 sur
les cartes (délégation capture dans today.js, fragments live
compris); sections dédiées dans le briefing du matin.

app/models.py

@@ -79,6 +79,13 @@ def init_db() -> None:
             CREATE INDEX IF NOT EXISTS idx_board_repo
                 ON board_state(repo_full_name, column_name);
 
+            CREATE TABLE IF NOT EXISTS today_picks (
+                pick_date TEXT NOT NULL,
+                repo_full_name TEXT NOT NULL,
+                issue_number INTEGER NOT NULL,
+                created_at TEXT NOT NULL DEFAULT (datetime('now')),
+                PRIMARY KEY (pick_date, repo_full_name, issue_number)
+            );
             CREATE TABLE IF NOT EXISTS kv_store (
                 key TEXT PRIMARY KEY,
                 value TEXT NOT NULL
@@ -239,6 +246,35 @@ def reconcile_board_state(
     return changed
 
 
+def get_picks(pick_date: str) -> list[dict]:
+    """The day's focus picks (issue #5), in pinning order."""
+    with get_db() as conn:
+        rows = conn.execute(
+            "SELECT repo_full_name, issue_number FROM today_picks "
+            "WHERE pick_date = ? ORDER BY created_at, repo_full_name, issue_number",
+            (pick_date,),
+        ).fetchall()
+    return [dict(row) for row in rows]
+
+
+def add_pick(pick_date: str, repo_full_name: str, issue_number: int) -> None:
+    with get_db() as conn:
+        conn.execute(
+            "INSERT OR IGNORE INTO today_picks "
+            "(pick_date, repo_full_name, issue_number) VALUES (?, ?, ?)",
+            (pick_date, repo_full_name, issue_number),
+        )
+
+
+def remove_pick(pick_date: str, repo_full_name: str, issue_number: int) -> None:
+    with get_db() as conn:
+        conn.execute(
+            "DELETE FROM today_picks WHERE pick_date = ? "
+            "AND repo_full_name = ? AND issue_number = ?",
+            (pick_date, repo_full_name, issue_number),
+        )
+
+
 def get_kv(key: str) -> str | None:
     with get_db() as conn:
         row = conn.execute(