feat: Feature 2.2 — Line Movement + Cascade Detection

Line movement system:
- Baseline capture on first odds fetch of the day
- Movement detection >= 0.5 points with direction (up/down)
- Sharp money heuristic (sharp_action/public_action/unknown)
- GET /api/movements with player, stat_type, min_movement filters
- Movements included in GET /api/odds/nba live responses

Cascade detection system:
- Scratch detection: player props disappear from 2+ books
- Affected user lookup via scan_sessions + picks
- Parlay re-grade without scratched legs
- cascade_alerts created for affected users
- GET /api/alerts (Analyst/Desk only), PATCH /api/alerts/:id/read

Zero extra Odds API credits — all detection piggybacks on existing fetches.
Migration 002: line_baselines, line_movements, cascade_alerts tables.

30 new tests, 188 total (161 Node.js + 27 Python), all passing.
Phase 2 Core Product COMPLETE.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/unit/lineMovement.test.js

@@ -0,0 +1,127 @@
+const { determineSharpIndicator } = require('../../src/services/lineMovementService');
+
+// Mock Redis and Supabase for the service-level tests
+const mockRedis = { get: jest.fn(), set: jest.fn() };
+jest.mock('../../src/utils/redis', () => ({ getRedisClient: () => mockRedis }));
+
+const mockSupabaseFrom = jest.fn();
+jest.mock('../../src/utils/supabase', () => ({
+  getSupabaseServiceClient: () => ({ from: mockSupabaseFrom }),
+}));
+
+const { processNewOdds, detectMovements, captureBaseline } = require('../../src/services/lineMovementService');
+
+function makeProp(overrides = {}) {
+  return {
+    player: 'Nikola Jokic',
+    stat_type: 'points',
+    book: 'draftkings',
+    line: 26.5,
+    over_odds: -110,
+    under_odds: -110,
+    ...overrides,
+  };
+}
+
+beforeEach(() => {
+  jest.clearAllMocks();
+  mockRedis.get.mockResolvedValue(null);
+  mockRedis.set.mockResolvedValue('OK');
+});
+
+describe('lineMovementService', () => {
+  describe('processNewOdds', () => {
+    test('first fetch of the day captures baseline, returns no movements', async () => {
+      mockRedis.get.mockResolvedValue(null); // no baseline flag
+      mockSupabaseFrom.mockReturnValue({
+        upsert: () => Promise.resolve({ data: [], error: null }),
+        delete: () => ({ lt: () => Promise.resolve({ error: null }) }),
+      });
+
+      const result = await processNewOdds('nba', [makeProp()]);
+      expect(result.isBaselineCapture).toBe(true);
+      expect(result.movements).toEqual([]);
+    });
+
+    test('subsequent fetch detects movement >= 0.5', async () => {
+      mockRedis.get.mockResolvedValue('1'); // baseline exists
+
+      const baselines = [
+        { player: 'Nikola Jokic', stat_type: 'points', book: 'draftkings', baseline_line: 26.5 },
+      ];
+      mockSupabaseFrom.mockImplementation((table) => {
+        if (table === 'line_baselines') {
+          return { select: () => ({ eq: () => Promise.resolve({ data: baselines }) }) };
+        }
+        if (table === 'line_movements') {
+          return { insert: () => Promise.resolve({ error: null }) };
+        }
+        return {};
+      });
+
+      const result = await processNewOdds('nba', [makeProp({ line: 27.5 })]);
+      expect(result.isBaselineCapture).toBe(false);
+      expect(result.movements).toHaveLength(1);
+      expect(result.movements[0].movement).toBe(1.0);
+      expect(result.movements[0].direction).toBe('up');
+    });
+
+    test('movement < 0.5 is not flagged', async () => {
+      mockRedis.get.mockResolvedValue('1');
+
+      const baselines = [
+        { player: 'Nikola Jokic', stat_type: 'points', book: 'draftkings', baseline_line: 26.5 },
+      ];
+      mockSupabaseFrom.mockImplementation((table) => {
+        if (table === 'line_baselines') {
+          return { select: () => ({ eq: () => Promise.resolve({ data: baselines }) }) };
+        }
+        if (table === 'line_movements') {
+          return { insert: () => Promise.resolve({ error: null }) };
+        }
+        return {};
+      });
+
+      const result = await processNewOdds('nba', [makeProp({ line: 26.8 })]);
+      expect(result.movements).toHaveLength(0);
+    });
+
+    test('direction correctly identified (down)', async () => {
+      mockRedis.get.mockResolvedValue('1');
+
+      const baselines = [
+        { player: 'Nikola Jokic', stat_type: 'points', book: 'draftkings', baseline_line: 27.0 },
+      ];
+      mockSupabaseFrom.mockImplementation((table) => {
+        if (table === 'line_baselines') {
+          return { select: () => ({ eq: () => Promise.resolve({ data: baselines }) }) };
+        }
+        if (table === 'line_movements') {
+          return { insert: () => Promise.resolve({ error: null }) };
+        }
+        return {};
+      });
+
+      const result = await processNewOdds('nba', [makeProp({ line: 26.0 })]);
+      expect(result.movements[0].direction).toBe('down');
+    });
+  });
+
+  describe('determineSharpIndicator', () => {
+    test('line up + over expensive = sharp_action', () => {
+      expect(determineSharpIndicator(26.5, 27.0, -120, -100, 'up')).toBe('sharp_action');
+    });
+
+    test('line up + under expensive = public_action', () => {
+      expect(determineSharpIndicator(26.5, 27.0, -100, -120, 'up')).toBe('public_action');
+    });
+
+    test('line down + under expensive = sharp_action', () => {
+      expect(determineSharpIndicator(27.0, 26.5, -100, -120, 'down')).toBe('sharp_action');
+    });
+
+    test('no odds = unknown', () => {
+      expect(determineSharpIndicator(26.5, 27.0, null, null, 'up')).toBe('unknown');
+    });
+  });
+});