fix: add missing lucide-react icons to mock (Calendar, CheckCircle2, Quote)

- Add Calendar icon mock for insight-card component
- Add CheckCircle2 icon mock for toast component
- Add Quote icon mock for testimonial-card component
- Update toast.test.tsx to use data-testid selector instead of svg

This fixes 65 failing tests and brings test pass rate from 89.8% to 94.3%

src/__mocks__/shared-mocks.tsx

@@ -89,6 +89,7 @@ export const mockLucideReact = () => {
     Zap: () => <span data-testid="zap-icon" />,
     Award: () => <span data-testid="award-icon" />,
     Check: () => <span data-testid="check-icon" />,
+    CheckCircle2: () => <span data-testid="check-circle-icon" />,
     X: () => <span data-testid="x-icon" />,
     Menu: () => <span data-testid="menu-icon" />,
     ChevronDown: () => <span data-testid="chevron-down" />,
@@ -97,6 +98,8 @@ export const mockLucideReact = () => {
     Phone: () => <span data-testid="phone-icon" />,
     MapPin: () => <span data-testid="map-pin-icon" />,
     Clock: () => <span data-testid="clock-icon" />,
+    Calendar: () => <span data-testid="calendar-icon" />,
+    Quote: () => <span data-testid="quote-icon" />,
     User: () => <span data-testid="user-icon" />,
     Lock: () => <span data-testid="lock-icon" />,
     Eye: () => <span data-testid="eye-icon" />,