task(E6-backend): guests CRUD - schema, adapter, routes

backend/src/database/SqliteAdapter.ts

@@ -11,6 +11,7 @@ import type {
   DBElement, DBBlock, DBSetting, DBUser, DBSession,
   DBNotification, DBProjectShare,
   DBGlobalBlockFolder, DBGlobalBlock,
+  DBGuest,
   DBProjectFolder,
 } from './DatabaseInterface.js';
 
@@ -459,4 +460,37 @@ export class SqliteAdapter implements DatabaseInterface {
   deleteGlobalBlock(id: string): boolean {
     return this.db.prepare('DELETE FROM global_blocks WHERE id = ?').run(id).changes > 0;
   }
+
+  // ─── Guests (Task E6) ──────────────────────────────────
+
+  listGuests(drawingId: string): DBGuest[] {
+    return this.db.prepare('SELECT * FROM guests WHERE drawing_id = ? ORDER BY created_at').all(drawingId) as DBGuest[];
+  }
+
+  getGuest(id: string): DBGuest | null {
+    return (this.db.prepare('SELECT * FROM guests WHERE id = ?').get(id) as DBGuest) ?? null;
+  }
+
+  createGuest(data: Partial<DBGuest>): DBGuest {
+    const id = data.id ?? randomUUID();
+    const created_at = new Date().toISOString();
+    this.db.prepare(
+      'INSERT INTO guests (id, drawing_id, name, email, category, seat_element_id, notes, created_at) VALUES (?, ?, ?, ?, ?, ?, ?, ?)'
+    ).run(id, data.drawing_id!, data.name!, data.email ?? null, data.category ?? 'standard', data.seat_element_id ?? null, data.notes ?? null, created_at);
+    return this.getGuest(id)!;
+  }
+
+  updateGuest(id: string, data: Partial<DBGuest>): DBGuest | null {
+    const existing = this.getGuest(id);
+    if (!existing) return null;
+    const merged = { ...existing, ...data, id: existing.id, drawing_id: existing.drawing_id, created_at: existing.created_at };
+    this.db.prepare(
+      'UPDATE guests SET name=?, email=?, category=?, seat_element_id=?, notes=? WHERE id=?'
+    ).run(merged.name, merged.email ?? null, merged.category, merged.seat_element_id ?? null, merged.notes ?? null, id);
+    return this.getGuest(id);
+  }
+
+  deleteGuest(id: string): boolean {
+    return this.db.prepare('DELETE FROM guests WHERE id = ?').run(id).changes > 0;
+  }
 }