feat(payments): fix Polar webhook + pre-fill checkout email

- Fix customer email path: was data.customer_email, is actually
  data.customer.email per Polar v1 API schema
- Add resolveUser() helper: tries polar_customer_id → email → external_id
- Add subscription.active and subscription.canceled event handling
- Handle order.created for fast-path pro upgrade on purchase
- Profile page: fetch user email + polarCustomerId from PocketBase
- Profile page: pre-fill ?customer_email= on checkout links
- Profile page: link to polar.sh/purchases for existing customers

ui/src/routes/api/webhooks/polar/+server.ts

@@ -1,12 +1,20 @@
 import type { RequestHandler } from './$types';
 import { log } from '$lib/server/logger';
-import { verifyPolarWebhook, handleSubscriptionEvent } from '$lib/server/polar';
+import { verifyPolarWebhook, handleSubscriptionEvent, handleOrderCreated } from '$lib/server/polar';
 
 /**
  * POST /api/webhooks/polar
  *
  * Receives Polar subscription lifecycle events and syncs user roles in PocketBase.
  * Signature is verified via HMAC-SHA256 before any processing.
+ *
+ * Handled events:
+ *   subscription.created  — new subscription (status may be "active" or "trialing")
+ *   subscription.active   — subscription became active (e.g. after payment)
+ *   subscription.updated  — catch-all: cancellations, renewals, plan changes
+ *   subscription.canceled — cancel_at_period_end=true, still active until period end
+ *   subscription.revoked  — access ended, downgrade to free
+ *   order.created         — purchase / subscription_create: fast-path upgrade
  */
 export const POST: RequestHandler = async ({ request }) => {
 	const rawBody = await request.text();
@@ -30,14 +38,15 @@ export const POST: RequestHandler = async ({ request }) => {
 	try {
 		switch (type) {
 			case 'subscription.created':
+			case 'subscription.active':
 			case 'subscription.updated':
+			case 'subscription.canceled':
 			case 'subscription.revoked':
-				await handleSubscriptionEvent(type, data as unknown as Parameters<typeof handleSubscriptionEvent>[1]);
+				await handleSubscriptionEvent(type, data as Parameters<typeof handleSubscriptionEvent>[1]);
 				break;
 
 			case 'order.created':
-				// One-time purchases — no role change needed for now
-				log.info('polar', 'order.created (no action)', { orderId: data.id });
+				await handleOrderCreated(data as Parameters<typeof handleOrderCreated>[0]);
 				break;
 
 			default: