Add Misty & Arina NPCs, fix tier gating, babysit actions, Robbie filter, streak/scheduler bugs

Misty & Arina: random encounter NPCs triggered by chat message counting
(5-10 msg threshold, 7-day cooldown, 7.5% roll). Misty asks for €100 —
accept gives 7-day arena buff (20% gourmet food heals gear + 5 enemy dmg),
decline gives 7-day debuff (20% crowd revenge damage). Arina asks for €5000 —
accept gives 7-day sniper buff (8% instant kill in arena). Effects integrate
into arena round resolution after combat roll; sniper overrides death.

Other fixes:
- Tier gating now uses base skill only — buffs improve success, not access
- Babysitter uses all harvest actions (3/day, 4 on holidays) instead of 1
- Robbie collects all non-equipped items, not just slotted gear
- Robbie timing: fire on first tick >= target hour, not exact minute match
- Streak: dead players who acted still get streak credit
- Streak: dead players skip shame DM (use LastDeathDate, not Alive flag)
- Midnight ticker: in-memory date cache prevents 1439 wasted DB checks/day
- T1 loot values ~3x across all activities to close T1/T2 gap

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

internal/plugin/adventure_test.go

@@ -127,6 +127,35 @@ func TestAdvIsEligible_NoPenalty(t *testing.T) {
 	}
 }
 
+func TestAdvIsEligible_BonusesDontUnlockTiers(t *testing.T) {
+	char := &AdventureCharacter{MiningSkill: 1}
+	equip := map[EquipmentSlot]*AdvEquipment{}
+	loc := &AdvLocation{Activity: AdvActivityMining, MinLevel: 8, MinEquipTier: 0}
+	bonuses := &AdvBonusSummary{MiningBonus: 10} // +10 would make effective 11, but base is 1
+
+	eligible, _ := advIsEligible(char, equip, loc, bonuses)
+	if eligible {
+		t.Error("bonuses should not unlock tiers — base mining 1 should not access min level 8")
+	}
+}
+
+func TestAdvIsEligible_BonusesDontAffectPenaltyZone(t *testing.T) {
+	char := &AdventureCharacter{CombatLevel: 21} // base 21, min 20 → penalty (21-20=1 < 3)
+	equip := map[EquipmentSlot]*AdvEquipment{
+		SlotWeapon: {Tier: 2, Condition: 100},
+	}
+	loc := &AdvLocation{Activity: AdvActivityDungeon, MinLevel: 20, MinEquipTier: 0}
+	bonuses := &AdvBonusSummary{CombatBonus: 10} // +10 would make effective 31, but penalty uses base
+
+	eligible, penalty := advIsEligible(char, equip, loc, bonuses)
+	if !eligible {
+		t.Error("should be eligible at base combat 21 for min 20")
+	}
+	if !penalty {
+		t.Error("should still be in penalty zone — bonuses don't affect penalty calculation")
+	}
+}
+
 func TestCalculateAdvProbabilities_SumsTo100(t *testing.T) {
 	char := &AdventureCharacter{CombatLevel: 10}
 	equip := map[EquipmentSlot]*AdvEquipment{