feat(db): introduce item_claims for quantity-aware claims; supersede inline claim columns

lib/db/index.ts

@@ -113,6 +113,25 @@ export async function initializeDatabase() {
       )
     `);
 
+    // Create item_claims table
+    sqlite.exec(`
+      CREATE TABLE IF NOT EXISTS item_claims (
+        id TEXT PRIMARY KEY NOT NULL,
+        item_id TEXT NOT NULL,
+        guest_id TEXT NOT NULL,
+        quantity INTEGER DEFAULT 1 NOT NULL,
+        note TEXT,
+        is_purchased INTEGER DEFAULT 0 NOT NULL,
+        claimed_at INTEGER DEFAULT (unixepoch()) NOT NULL,
+        updated_at INTEGER DEFAULT (unixepoch()) NOT NULL,
+        FOREIGN KEY (item_id) REFERENCES wishlist_items(id) ON DELETE CASCADE,
+        FOREIGN KEY (guest_id) REFERENCES guests(id) ON DELETE CASCADE,
+        UNIQUE(item_id, guest_id)
+      )
+    `);
+    sqlite.exec('CREATE INDEX IF NOT EXISTS idx_item_claims_item ON item_claims(item_id)');
+    sqlite.exec('CREATE INDEX IF NOT EXISTS idx_item_claims_guest ON item_claims(guest_id)');
+
     // Run migrations for existing databases
     try {
       const columns = sqlite.pragma('table_info(wishlists)') as Array<{ name: string }>;
@@ -157,6 +176,32 @@ export async function initializeDatabase() {
         }
         console.log('ℹ️  Legacy claim columns nullified (claimed_by_name / claimed_by_token)');
       }
+
+      // Move any existing inline claims into item_claims (forward-migration), then nullify the inline columns
+      const itemColsAfter = sqlite.pragma('table_info(wishlist_items)') as Array<{ name: string }>;
+      const stillHasClaimedByGuestId = itemColsAfter.some((c) => c.name === 'claimed_by_guest_id');
+      if (stillHasClaimedByGuestId) {
+        sqlite.exec(`
+          INSERT INTO item_claims (id, item_id, guest_id, quantity, note, is_purchased, claimed_at, updated_at)
+          SELECT
+            lower(hex(randomblob(16))),
+            wi.id,
+            wi.claimed_by_guest_id,
+            1,
+            wi.claimed_by_note,
+            wi.is_purchased,
+            COALESCE(wi.claimed_at, unixepoch()),
+            unixepoch()
+          FROM wishlist_items wi
+          WHERE wi.claimed_by_guest_id IS NOT NULL
+            AND NOT EXISTS (
+              SELECT 1 FROM item_claims ic
+              WHERE ic.item_id = wi.id AND ic.guest_id = wi.claimed_by_guest_id
+            )
+        `);
+        sqlite.exec('UPDATE wishlist_items SET claimed_by_guest_id = NULL, claimed_by_note = NULL, claimed_at = NULL, is_purchased = 0');
+        console.log('ℹ️  Migrated inline claims into item_claims and cleared inline claim columns');
+      }
     } catch (migrationError) {
       console.log('Migration already applied or not needed');
     }