feat(enakgame): budget controller recommendations and analytics

EnakGame phase 9 of docs/tasks-enakgame.md (EG-901 to EG-903).

Budget Controller (EG-901, EG-902)
- GET /marketing/enakgame/budgets/:id/recommendation, GLOBAL budgets only: the
  multiplier (budget − realized) / (forecast − realized), within one step of 1,
  rounded down to two decimals, either way. Shows each game's new rules.
- POST .../recommendation/accept with the multiplier the admin saw: recomputed in the
  transaction, then one new ACTIVE version per game, the old one RETIRED, audited
  with source budget_controller and RECOMMENDATION_ACCEPTED on the budget.
- Migration 000112: base_config_id, multiplier and budget_id on
  game_reward_configs. Rules are always scaled from the admin's last version, so
  rounding does not compound and min/max are against what the admin set.
- Guardrails in game_budgets.thresholds: max_step_percent 10, min/max multiplier
  50-150%, cooldown_days 7 per organization. Provisional pending RFC §19.2 #4.
- RewardCalculator.Scale for the four reward types: amounts only, rounded down.

Analytics (EG-903)
- GET /marketing/enakgame/analytics/games and /analytics/economy over a range of
  Asia/Jakarta days (at most 366), from game_sessions and the wallet ledger.
- Migrations 000113 (game_sessions by organization and start) and 000114
  (wallet_transactions by organization and time, CONCURRENTLY).

The Postgres tests for accepting and analytics were not run: no test database here.
Migrations 000112-000114 have not been run anywhere.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/processor/enakgame_analytics_db_test.go

@@ -0,0 +1,80 @@
+package processor
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"apskel-pos-be/internal/constants"
+	"apskel-pos-be/internal/entities"
+	"apskel-pos-be/internal/models"
+	"apskel-pos-be/internal/repository"
+)
+
+// EG-903 against Postgres. Needs TEST_DATABASE_URL; see
+// internal/repository/wallet_repository_test.go.
+func TestEnakGameAnalytics_AgainstPostgres(t *testing.T) {
+	e := newEnakGameEnv(t)
+	ctx := e.ctx()
+	analytics := NewEnakGameAnalyticsProcessor(repository.NewEnakGameAnalyticsRepository(e.db))
+
+	// Sessions and ledger rows are stamped with the test clock and the database's,
+	// both now: a range around today holds them all.
+	today := walletDay(e.now)
+	q := models.EnakGameAnalyticsQuery{From: today.AddDate(0, 0, -1).Format("2006-01-02"), To: today.AddDate(0, 0, 1).Format("2006-01-02")}
+
+	tap := e.gameWith("tap", entities.GameResultRules{}, constants.GameRewardTypeFixed, `{"amount": 10}`, 10)
+	run := e.gameWith("run", entities.GameResultRules{}, constants.GameRewardTypeScoreBased,
+		`{"bands": [{"min": 0, "max": 100, "amount": 5}, {"min": 101, "amount": 20}]}`, 20)
+	e.coins(e.alice, 10, nil)
+	e.coins(e.bob, 10, nil)
+	for i, key := range []string{"tap-1", "tap-2"} {
+		started, err := e.sessions.Start(ctx, e.alice, tap.ID, key)
+		require.NoError(t, err, i)
+		_, err = e.sessions.Complete(ctx, e.alice, started.SessionID, models.GameSessionCompleteInput{})
+		require.NoError(t, err, i)
+	}
+	_, err := e.sessions.Start(ctx, e.bob, tap.ID, "tap-3") // left open
+	require.NoError(t, err)
+	started, err := e.sessions.Start(ctx, e.alice, run.ID, "run-1")
+	require.NoError(t, err)
+	_, err = e.sessions.Complete(ctx, e.alice, started.SessionID, models.GameSessionCompleteInput{Score: ptr(int64(150))})
+	require.NoError(t, err)
+
+	games, err := analytics.Games(ctx, e.orgA, q)
+	require.NoError(t, err)
+	assert.Equal(t, models.EnakGameStats{
+		Plays: 4, Completed: 3, Players: 2, AverageScore: ptr(150.0),
+		AverageReward: 13.33, RewardPerPlay: 10, CoinIssued: 40, EntryCostPaid: 8,
+	}, games.Totals)
+	require.Len(t, games.Games, 2)
+	assert.Equal(t, tap.ID, games.Games[0].GameID, "most played first")
+	assert.EqualValues(t, 3, games.Games[0].Plays)
+	assert.EqualValues(t, 2, games.Games[0].Players)
+	assert.Nil(t, games.Games[0].AverageScore, "FIXED reports no score")
+	assert.EqualValues(t, 20, games.Games[1].CoinIssued)
+
+	one, err := analytics.Games(ctx, e.orgA, models.EnakGameAnalyticsQuery{From: q.From, To: q.To, GameID: run.ID.String()})
+	require.NoError(t, err)
+	assert.EqualValues(t, 1, one.Totals.Plays)
+	require.Len(t, one.Games, 1)
+
+	other, err := analytics.Games(ctx, e.orgB, q)
+	require.NoError(t, err)
+	assert.Zero(t, other.Totals.Plays, "another organization's sessions never show")
+	assert.Empty(t, other.Games)
+
+	economy, err := analytics.Economy(ctx, e.orgA, q)
+	require.NoError(t, err)
+	assert.Equal(t, models.EnakGameCoinFlows{
+		Generated: 60, GameRewards: 40, SpentOnGames: 8, Spent: 8, Outstanding: 52,
+	}, economy.Coin)
+	assert.Zero(t, economy.Point)
+
+	// A range before anything happened.
+	empty, err := analytics.Economy(ctx, e.orgA, models.EnakGameAnalyticsQuery{From: "2020-01-01", To: "2020-01-31"})
+	require.NoError(t, err)
+	assert.Zero(t, empty.Coin)
+	assert.Empty(t, empty.ByType)
+}