feat(loyalty): refactor analytics into shared template and add merchant stats API

Extract analytics stat cards, points activity, and location breakdown
into a shared partial used by admin, merchant, and store dashboards.
Add merchant stats API endpoint and client-side merchant filter on admin
analytics page. Extend stats schema with new_this_month and
estimated_liability_cents fields.

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

app/modules/loyalty/static/merchant/js/loyalty-analytics.js

@@ -0,0 +1,109 @@
+// app/modules/loyalty/static/merchant/js/loyalty-analytics.js
+// noqa: js-006 - async init pattern is safe, loadData has try/catch
+
+const loyaltyAnalyticsLog = window.LogConfig.loggers.loyaltyAnalytics || window.LogConfig.createLogger('loyaltyAnalytics');
+
+function merchantLoyaltyAnalytics() {
+    return {
+        ...data(),
+        currentPage: 'loyalty-analytics',
+
+        program: null,
+        locations: [],
+
+        stats: {
+            total_cards: 0,
+            active_cards: 0,
+            new_this_month: 0,
+            total_points_issued: 0,
+            total_points_redeemed: 0,
+            total_points_balance: 0,
+            points_issued_30d: 0,
+            points_redeemed_30d: 0,
+            transactions_30d: 0,
+            avg_points_per_member: 0,
+            estimated_liability_cents: 0,
+        },
+
+        loading: false,
+        error: null,
+
+        get redemptionRate() {
+            if (this.stats.points_issued_30d === 0) return 0;
+            return Math.round((this.stats.points_redeemed_30d / this.stats.points_issued_30d) * 100);
+        },
+
+        get issuedPercentage() {
+            const total = this.stats.points_issued_30d + this.stats.points_redeemed_30d;
+            if (total === 0) return 50;
+            return Math.round((this.stats.points_issued_30d / total) * 100);
+        },
+
+        get redeemedPercentage() {
+            return 100 - this.issuedPercentage;
+        },
+
+        async init() {
+            loyaltyAnalyticsLog.info('=== MERCHANT LOYALTY ANALYTICS PAGE INITIALIZING ===');
+            if (window._loyaltyAnalyticsInitialized) return;
+            window._loyaltyAnalyticsInitialized = true;
+
+            this.loadMenuConfig();
+            await this.loadStats();
+            loyaltyAnalyticsLog.info('=== MERCHANT LOYALTY ANALYTICS PAGE INITIALIZATION COMPLETE ===');
+        },
+
+        async loadStats() {
+            this.loading = true;
+            this.error = null;
+
+            try {
+                const response = await apiClient.get('/merchants/loyalty/stats');
+                if (response) {
+                    this.program = response.program || null;
+                    this.locations = response.locations || [];
+
+                    const totalBalance = (response.total_points_issued || 0) - (response.total_points_redeemed || 0);
+                    const avgPoints = response.active_cards > 0
+                        ? Math.round(totalBalance / response.active_cards * 100) / 100
+                        : 0;
+
+                    this.stats = {
+                        total_cards: response.total_cards || 0,
+                        active_cards: response.active_cards || 0,
+                        new_this_month: response.new_this_month || 0,
+                        total_points_issued: response.total_points_issued || 0,
+                        total_points_redeemed: response.total_points_redeemed || 0,
+                        total_points_balance: totalBalance,
+                        points_issued_30d: response.points_issued_30d || 0,
+                        points_redeemed_30d: response.points_redeemed_30d || 0,
+                        transactions_30d: response.transactions_30d || 0,
+                        avg_points_per_member: avgPoints,
+                        estimated_liability_cents: response.estimated_liability_cents || 0,
+                    };
+                    loyaltyAnalyticsLog.info('Merchant stats loaded');
+                }
+            } catch (error) {
+                if (error.status === 404) {
+                    loyaltyAnalyticsLog.info('No program found');
+                    this.program = null;
+                } else {
+                    loyaltyAnalyticsLog.error('Failed to load stats:', error);
+                    this.error = error.message || 'Failed to load analytics';
+                }
+            } finally {
+                this.loading = false;
+            }
+        },
+
+        formatNumber(num) {
+            if (num === null || num === undefined) return '0';
+            return new Intl.NumberFormat('en-US').format(num);
+        }
+    };
+}
+
+if (!window.LogConfig.loggers.loyaltyAnalytics) {
+    window.LogConfig.loggers.loyaltyAnalytics = window.LogConfig.createLogger('loyaltyAnalytics');
+}
+loyaltyAnalyticsLog.info('Merchant loyalty analytics module loaded');