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/reward_calculator_test.go

@@ -144,3 +144,38 @@ func TestRewardCalculator_RejectsInvalidRules(t *testing.T) {
 		assert.ErrorIs(t, err, ErrInvalidRewardRules, name)
 	}
 }
+
+// EG-902: the Budget Controller scales amounts, rounded down, and nothing else.
+func TestRewardCalculator_Scale(t *testing.T) {
+	for name, tc := range map[string]struct {
+		rewardType, rules string
+		multiplier        int64
+		want              string
+	}{
+		"FIXED ×0.9":    {constants.GameRewardTypeFixed, `{"amount": 10}`, 9_000, `{"amount":9}`},
+		"FIXED rounds":  {constants.GameRewardTypeFixed, `{"amount": 5}`, 9_000, `{"amount":4}`},
+		"FIXED to zero": {constants.GameRewardTypeFixed, `{"amount": 1}`, 9_000, `{"amount":0}`},
+		"FIXED ×1.1":    {constants.GameRewardTypeFixed, `{"amount": 10}`, 11_000, `{"amount":11}`},
+		"FIXED ×1":      {constants.GameRewardTypeFixed, `{"amount": 7}`, 10_000, `{"amount":7}`},
+		"SCORE_BASED":   {constants.GameRewardTypeScoreBased, `{"bands": [{"min": 0, "max": 100, "amount": 1}, {"min": 101, "amount": 20}]}`, 8_100, `{"bands":[{"min":0,"max":100,"amount":0},{"min":101,"amount":16}]}`},
+		"OUTCOME_BASED": {constants.GameRewardTypeOutcomeBased, `{"outcomes": {"PERFECT": 20, "GOOD": 10, "FAIL": 0}}`, 9_000, `{"outcomes":{"FAIL":0,"GOOD":9,"PERFECT":18}}`},
+		"PROBABILITY":   {constants.GameRewardTypeProbability, `{"table": [{"weight": 1, "amount": 1000}, {"weight": 999, "amount": 0}]}`, 8_500, `{"table":[{"weight":1,"amount":850},{"weight":999,"amount":0}]}`},
+	} {
+		c, err := RewardCalculatorFor(tc.rewardType)
+		require.NoError(t, err)
+		scaled, err := c.Scale(json.RawMessage(tc.rules), tc.multiplier)
+		require.NoError(t, err, name)
+		assert.JSONEq(t, tc.want, string(scaled), name)
+		assert.NoError(t, c.Validate(scaled), "%s: scaled rules stay valid", name)
+	}
+
+	c, _ := RewardCalculatorFor(constants.GameRewardTypeFixed)
+	_, err := c.Scale(json.RawMessage(`{"amount": 9223372036854775807}`), 15_000)
+	assert.ErrorIs(t, err, ErrInvalidRewardRules, "overflow is refused, not wrapped")
+	_, err = c.Scale(json.RawMessage(`{"amount": -1}`), 9_000)
+	assert.ErrorIs(t, err, ErrInvalidRewardRules)
+
+	v, err := scaleRewardAmount(math.MaxInt64/15_000, 15_000)
+	require.NoError(t, err)
+	assert.EqualValues(t, math.MaxInt64/15_000*15_000/10_000, v)
+}