feat: BoltDB store — player profiles and run rankings

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

store/db_test.go

@@ -0,0 +1,55 @@
+package store
+
+import (
+	"os"
+	"testing"
+)
+
+func TestPlayerProfile(t *testing.T) {
+	db, err := Open("test.db")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		db.Close()
+		os.Remove("test.db")
+	}()
+
+	err = db.SaveProfile("SHA256:abc123", "TestPlayer")
+	if err != nil {
+		t.Fatal(err)
+	}
+	name, err := db.GetProfile("SHA256:abc123")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if name != "TestPlayer" {
+		t.Errorf("Name: got %q, want %q", name, "TestPlayer")
+	}
+}
+
+func TestRanking(t *testing.T) {
+	db, err := Open("test_rank.db")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		db.Close()
+		os.Remove("test_rank.db")
+	}()
+
+	db.SaveRun("Alice", 20, 1500)
+	db.SaveRun("Bob", 15, 1000)
+	db.SaveRun("Charlie", 20, 2000)
+
+	rankings, err := db.TopRuns(10)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(rankings) != 3 {
+		t.Errorf("Rankings: got %d, want 3", len(rankings))
+	}
+	if rankings[0].Player != "Charlie" {
+		t.Errorf("Top player: got %q, want Charlie", rankings[0].Player)
+	}
+}