server: missions — type configs, level gate, loot, fine on failure, abandon

Each mission type now has a typeConfig (moneyFactor, xpFactor, repFactor,
riskShift, requiredItemChance, lootChance). startMission checks minLevel.
claimMission awards loot items on success; applies a police-scaled fine
on failure. New abandonMission endpoint (POST /:id/abandon, −1 rep).
computeSuccessChance extracted for reuse between listAvailable and claim.
Narrative template pool expanded (4 templates × 4 types).

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

server/src/config/gameBalance.ts

@@ -97,9 +97,65 @@ export const balance = {
     /** Ricompensa XP: base + difficulty * perDifficulty */
     rewardXpBase: 20,
     rewardXpPerDifficulty: 30,
-    /** probabilità che una missione DELIVERY/SMUGGLING richieda oggetti */
-    requiredItemChance: 0.4,
     requiredItemQuantityMax: 3,
+    /**
+     * Carattere meccanico di ogni tipo di missione:
+     * - moneyFactor/xpFactor/repFactor: moltiplicatori delle ricompense
+     * - riskShift: spostamento del rischio base
+     * - requiredItemChance: probabilità che serva merce dall'inventario
+     * - lootChance/lootQuantityMax: probabilità e quantità del bottino in merce
+     */
+    typeConfig: {
+      DELIVERY: {
+        moneyFactor: 1.0,
+        xpFactor: 1.0,
+        repFactor: 1,
+        riskShift: -0.05,
+        requiredItemChance: 0.6,
+        lootChance: 0,
+        lootQuantityMax: 0,
+      },
+      THEFT: {
+        moneyFactor: 0.6,
+        xpFactor: 1.0,
+        repFactor: 1,
+        riskShift: 0.05,
+        requiredItemChance: 0,
+        lootChance: 0.8,
+        lootQuantityMax: 2,
+      },
+      SMUGGLING: {
+        moneyFactor: 1.6,
+        xpFactor: 0.9,
+        repFactor: 1,
+        riskShift: 0.1,
+        requiredItemChance: 0.5,
+        lootChance: 0.25,
+        lootQuantityMax: 1,
+      },
+      INTEL: {
+        moneyFactor: 0.5,
+        xpFactor: 1.8,
+        repFactor: 2,
+        riskShift: -0.1,
+        requiredItemChance: 0,
+        lootChance: 0,
+        lootQuantityMax: 0,
+      },
+    },
+    /** livello minimo richiesto, indicizzato per difficoltà (1-5) */
+    minLevelByDifficulty: [1, 1, 1, 2, 4, 6],
+    /**
+     * Multa sul fallimento: rewardMoney * rewardFactor * pressione polizia,
+     * mai oltre il denaro posseduto dal giocatore.
+     */
+    failFine: {
+      rewardFactor: 0.3,
+    },
+    /** abbandono volontario di una missione attiva */
+    abandon: {
+      reputationLoss: 1,
+    },
     /**
      * Probabilità di successo al claim:
      *   chance = baseChance