Phase 6: Translate User Pages - exchange, trades, invites, profile

- Expand exchange.json with all exchange page strings (page, steps, detailsStep, bookingStep, confirmationStep, priceDisplay)
- Create trades.json translation files for es, en, ca
- Create invites.json translation files for es, en, ca
- Create profile.json translation files for es, en, ca
- Translate exchange page and all components (ExchangeDetailsStep, BookingStep, ConfirmationStep, StepIndicator, PriceDisplay)
- Translate trades page (titles, sections, buttons, status labels)
- Translate invites page (titles, sections, status badges, copy button)
- Translate profile page (form labels, hints, placeholders, messages)
- Update IntlProvider to load all new namespaces
- All frontend tests passing

frontend/app/exchange/components/StepIndicator.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import { CSSProperties } from "react";
+import { useTranslation } from "../../hooks/useTranslation";
 
 type WizardStep = "details" | "booking" | "confirmation";
 
@@ -58,6 +59,7 @@ const styles: Record<string, CSSProperties> = {
  * Shows which step the user is currently on and which steps are completed.
  */
 export function StepIndicator({ currentStep }: StepIndicatorProps) {
+  const t = useTranslation("exchange");
   return (
     <div style={styles.stepIndicator}>
       <div
@@ -67,7 +69,7 @@ export function StepIndicator({ currentStep }: StepIndicatorProps) {
         }}
       >
         <span style={styles.stepNumber}>1</span>
-        <span style={styles.stepLabel}>Exchange Details</span>
+        <span style={styles.stepLabel}>{t("steps.details")}</span>
       </div>
       <div style={styles.stepDivider} />
       <div
@@ -81,7 +83,7 @@ export function StepIndicator({ currentStep }: StepIndicatorProps) {
         }}
       >
         <span style={styles.stepNumber}>2</span>
-        <span style={styles.stepLabel}>Book Appointment</span>
+        <span style={styles.stepLabel}>{t("steps.booking")}</span>
       </div>
       <div style={styles.stepDivider} />
       <div
@@ -91,7 +93,7 @@ export function StepIndicator({ currentStep }: StepIndicatorProps) {
         }}
       >
         <span style={styles.stepNumber}>3</span>
-        <span style={styles.stepLabel}>Confirm</span>
+        <span style={styles.stepLabel}>{t("steps.confirm")}</span>
       </div>
     </div>
   );