Stage 5: Add Prisma integration and enhance mission management

- Introduced Prisma as a dependency in package.json and updated pnpm-lock.yaml.
- Created Prisma module and service for database interactions.
- Added initial Prisma schema and migration for user, survivor, mission, and related entities.
- Implemented throttling in the API using @nestjs/throttler for rate limiting.
- Enhanced mission management logic to utilize Prisma for database transactions.
- Updated missions controller and service to handle mission state and participant management.
- Added Twitch PubSub service for real-time updates on mission states.

libs/mission-logic/src/lib/encounter-resolver.spec.ts

@@ -198,6 +198,69 @@ describe('resolveEncounter', () => {
       expect(result.logText.length).toBeGreaterThan(0);
     }
   });
+
+  // Edge cases: modifier overflow / degenerate inputs
+  it('massive positive perk modifier clamps probability to 1 — never throws', () => {
+    const perk: Perk = {
+      id: '00000000-0000-4000-a000-000000000003',
+      key: 'overpowered',
+      name: '',
+      description: '',
+      tags: [],
+      modifiers: [{ target: 'successChance', type: 'additive', amount: 100 }],
+    };
+    const result = resolveEncounter(
+      makeInput({ encounter: { key: 'gen', baseProbability: 0.5, tags: [] },
+        survivor: { id: '00000000-0000-4000-a000-000000000002', state: 'active',
+          stats: { objectives: 5, survival: 5, altruism: 5 }, perkSlots: [perk], hookCount: 0 } })
+    );
+    expect(result.success).toBe(true); // clamped to 1 → always succeeds
+  });
+
+  it('massive negative perk modifier clamps probability to 0 — never throws', () => {
+    const perk: Perk = {
+      id: '00000000-0000-4000-a000-000000000003',
+      key: 'cursed',
+      name: '',
+      description: '',
+      tags: [],
+      modifiers: [{ target: 'successChance', type: 'additive', amount: -100 }],
+    };
+    const result = resolveEncounter(
+      makeInput({ encounter: { key: 'gen', baseProbability: 0.5, tags: [] },
+        survivor: { id: '00000000-0000-4000-a000-000000000002', state: 'active',
+          stats: { objectives: 5, survival: 5, altruism: 5 }, perkSlots: [perk], hookCount: 0 } })
+    );
+    expect(result.success).toBe(false); // clamped to 0 → always fails
+  });
+
+  it('empty perkSlots array is handled without error', () => {
+    expect(() =>
+      resolveEncounter(makeInput({ survivor: {
+        id: '00000000-0000-4000-a000-000000000002', state: 'active',
+        stats: { objectives: 5, survival: 5, altruism: 5 }, perkSlots: [], hookCount: 0,
+      } }))
+    ).not.toThrow();
+  });
+
+  it('sacrificed survivor produces no state change on failure', () => {
+    const result = resolveEncounter(makeInput({
+      encounter: { key: 'gen', baseProbability: 0, tags: [] },
+      survivor: { id: '00000000-0000-4000-a000-000000000002', state: 'sacrificed',
+        stats: { objectives: 1, survival: 1, altruism: 1 }, perkSlots: [], hookCount: 2 },
+    }));
+    expect(result.success).toBe(false);
+    expect(result.survivorStateChange).toBeNull();
+  });
+
+  it('idle survivor produces no state change on failure', () => {
+    const result = resolveEncounter(makeInput({
+      encounter: { key: 'gen', baseProbability: 0, tags: [] },
+      survivor: { id: '00000000-0000-4000-a000-000000000002', state: 'idle',
+        stats: { objectives: 1, survival: 1, altruism: 1 }, perkSlots: [], hookCount: 0 },
+    }));
+    expect(result.survivorStateChange).toBeNull();
+  });
 });
 
 // ── Property-based tests ──────────────────────────────────────────────────────