fix: remove manual project creation, smart sequence release, received-invoices schema fix

- Remove ProjectCreate page, POST /projects endpoint, and next-number endpoint
- Projects can only be created through orders (shared numbering sequence)
- Remove dead CreateProjectSchema and createProject service function
- Delete 'order' row from number_sequences (unused; code uses 'shared')
- Smart sequence release: decrement last_number only when deleting the highest number
- Fix received-invoices stats referencing non-existent is_deleted and amount_czk columns
- Update deploy instructions in CLAUDE.md (npm install, prisma migrate deploy)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/services/orders.service.ts

@@ -542,23 +542,10 @@ export async function deleteOrder(id: number) {
     await tx.orders.delete({ where: { id } });
   });
 
-  const releasedYears = new Set<number>();
   const year = existing.created_at
     ? new Date(existing.created_at).getFullYear()
     : new Date().getFullYear();
-  await releaseSharedNumber(year);
-  releasedYears.add(year);
-
-  // Release the linked project's shared number(s) too
-  for (const p of linkedProjects) {
-    const pYear = p.created_at
-      ? new Date(p.created_at).getFullYear()
-      : new Date().getFullYear();
-    if (!releasedYears.has(pYear)) {
-      await releaseSharedNumber(pYear);
-      releasedYears.add(pYear);
-    }
-  }
+  await releaseSharedNumber(year, existing.order_number ?? undefined);
 
   return { data: { id, order_number: existing.order_number } };
 }