Add multi-account usage dashboard

backend/internal/store/store_test.go

@@ -26,6 +26,104 @@ func TestSettings(t *testing.T) {
 	}
 }
 
+func TestAccountsAndPerAccountUsage(t *testing.T) {
+	s, err := Open(t.TempDir())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer s.DB.Close()
+	accounts, err := s.Accounts()
+	if err != nil || len(accounts) != 1 || accounts[0].ID != 1 {
+		t.Fatalf("default accounts = %#v, %v", accounts, err)
+	}
+	second, err := s.CreateAccount("Team workspace")
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, id := range []int64{1, second.ID} {
+		if _, err = s.DB.Exec("INSERT INTO daily_usage(account_id,date,total_tokens,fetched_at) VALUES(?,?,?,?)", id, "2026-08-13", id*100, 1); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err = s.DeleteAccount(second.ID); err != nil {
+		t.Fatal(err)
+	}
+	var count int
+	if err = s.DB.QueryRow("SELECT COUNT(*) FROM daily_usage WHERE account_id=?", second.ID).Scan(&count); err != nil || count != 0 {
+		t.Fatalf("usage was not cascaded: %d, %v", count, err)
+	}
+}
+
+func TestLegacyUsageMigratesToDefaultAccount(t *testing.T) {
+	dir := t.TempDir()
+	db, err := sql.Open("sqlite", filepath.Join(dir, "codex-helper.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err = db.Exec("CREATE TABLE daily_usage(date TEXT PRIMARY KEY,total_tokens INTEGER NOT NULL,fetched_at INTEGER NOT NULL); INSERT INTO daily_usage VALUES('2026-08-12',321,1)"); err != nil {
+		t.Fatal(err)
+	}
+	db.Close()
+	s, err := Open(dir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer s.DB.Close()
+	var accountID, tokens int64
+	if err = s.DB.QueryRow("SELECT account_id,total_tokens FROM daily_usage WHERE date='2026-08-12'").Scan(&accountID, &tokens); err != nil {
+		t.Fatal(err)
+	}
+	if accountID != 1 || tokens != 321 {
+		t.Fatalf("migrated row = account %d, tokens %d", accountID, tokens)
+	}
+}
+
+func TestPopulatedLegacyLimitSnapshotsMigrateToDefaultAccount(t *testing.T) {
+	dir := t.TempDir()
+	db, err := sql.Open("sqlite", filepath.Join(dir, "codex-helper.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	_, err = db.Exec(`
+		CREATE TABLE limit_snapshots (
+			id INTEGER PRIMARY KEY AUTOINCREMENT,
+			limit_id TEXT NOT NULL,
+			window_type TEXT NOT NULL,
+			used_percent REAL NOT NULL,
+			duration_mins INTEGER NOT NULL,
+			resets_at INTEGER NOT NULL,
+			fetched_at INTEGER NOT NULL
+		);
+		CREATE INDEX idx_limits_time ON limit_snapshots(fetched_at);
+		INSERT INTO limit_snapshots(id,limit_id,window_type,used_percent,duration_mins,resets_at,fetched_at)
+			VALUES(7,'codex','primary',42.5,300,1700000000,1699990000);
+	`)
+	if err != nil {
+		t.Fatal(err)
+	}
+	db.Close()
+
+	s, err := Open(dir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer s.DB.Close()
+	var id, accountID, duration int64
+	var limitID, window string
+	var used float64
+	err = s.DB.QueryRow("SELECT id,account_id,limit_id,window_type,used_percent,duration_mins FROM limit_snapshots").Scan(&id, &accountID, &limitID, &window, &used, &duration)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if id != 7 || accountID != 1 || limitID != "codex" || window != "primary" || used != 42.5 || duration != 300 {
+		t.Fatalf("migrated limit = id %d, account %d, %s/%s, %.1f, duration %d", id, accountID, limitID, window, used, duration)
+	}
+	var indexCount int
+	if err = s.DB.QueryRow("SELECT COUNT(*) FROM sqlite_master WHERE type='index' AND name='idx_limits_time'").Scan(&indexCount); err != nil || indexCount != 1 {
+		t.Fatalf("limit index was not recreated: %d, %v", indexCount, err)
+	}
+}
+
 func TestBackupIncludesCommittedWALData(t *testing.T) {
 	dir := t.TempDir()
 	s, err := Open(dir)