feat: add audio clip annotation view for dialect rating

src/lib/model/annotation.ts

@@ -0,0 +1,36 @@
+import { sqliteTable, text, integer, uniqueIndex } from 'drizzle-orm/sqlite-core';
+import { relations, sql } from 'drizzle-orm';
+import { dataset_entry } from './dataset_entry';
+
+export const annotation = sqliteTable(
+  'annotation',
+  {
+    id: integer('id').primaryKey({ autoIncrement: true }),
+    datasetEntryId: integer('dataset_entry_id')
+      .notNull()
+      .references(() => dataset_entry.id),
+    userId: text('user_id').notNull(),
+    rating: integer('rating').notNull(), // 1–5
+    dialectLabel: text('dialect_label').notNull(), // e.g. 'ch_be', 'ch_zh', …
+    createdAt: integer('created_at', { mode: 'timestamp' })
+      .notNull()
+      .default(sql`(unixepoch())`),
+  },
+  (table) => [
+    uniqueIndex('annotation_user_entry_dialect_idx').on(
+      table.userId,
+      table.datasetEntryId,
+      table.dialectLabel
+    ),
+  ]
+);
+
+export const annotationRelations = relations(annotation, ({ one }) => ({
+  datasetEntry: one(dataset_entry, {
+    fields: [annotation.datasetEntryId],
+    references: [dataset_entry.id],
+  }),
+}));
+
+export type Annotation = typeof annotation.$inferSelect;
+export type NewAnnotation = typeof annotation.$inferInsert;