Add 17 features: My Work view, card copy/numbering, calendar, bulk ops, custom fields, automations, webhooks, invites, import/export, and more

Features implemented across 6 batches:
- Batch A: Fix ColorPicker gradient sync, tenant custom logo, unarchive cards, board backgrounds
- Batch B: My Work view, card copy/duplicate, card numbering (BOARD-123)
- Batch C: Due date reminders (cron), card watching with notifications
- Batch D: Bulk card operations, column sorting, calendar view
- Batch E: Invite by link, board import/export (Pounce + Trello JSON)
- Batch F: Webhooks with HMAC signing, custom fields, automation rules engine

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

src/routes/api/boards/+server.ts

@@ -53,6 +53,7 @@ export const POST: RequestHandler = async ({ request, locals }) => {
 	}
 
 	const { title, description, visibility, categoryId, templateId } = result.data;
+	const cardPrefix = title.replace(/[^a-zA-Z]/g, '').toUpperCase().slice(0, 4) || 'CARD';
 
 	// Load template columns if templateId provided
 	let templateColumns: { title: string }[] = [];
@@ -77,6 +78,7 @@ export const POST: RequestHandler = async ({ request, locals }) => {
 				title,
 				description,
 				visibility,
+				cardPrefix,
 				...(categoryId ? { categoryId } : {}),
 				members: {
 					create: {