diff --git a/openspec/changes/user-accounts/tasks.md b/openspec/changes/user-accounts/tasks.md
index de59ca2..1c5b4ef 100644
--- a/openspec/changes/user-accounts/tasks.md
+++ b/openspec/changes/user-accounts/tasks.md
@@ -8,7 +8,7 @@
 
 - [x] 2.1 `[sonnet]` Add `users` table to Drizzle schema (`src/lib/db/schema.ts`) with UUID PK, email, password_hash, name, image, provider, provider_account_id, email_verified, created_at, updated_at
 - [x] 2.2 `[sonnet]` Add `user_id` (uuid, FK to users.id) column to `charts`, `annotations`, `annotation_types`, `span_annotations`, `span_label_types` in schema
-- [ ] 2.3 `[sonnet]` Replace unique constraints: `charts.name` → `(user_id, name)`, `annotation_types.name` → `(user_id, name)`, `span_label_types.name` → `(user_id, name)`
+- [x] 2.3 `[sonnet]` Replace unique constraints: `charts.name` → `(user_id, name)`, `annotation_types.name` → `(user_id, name)`, `span_label_types.name` → `(user_id, name)`
 - [ ] 2.4 `[haiku]` Generate Drizzle migration with `drizzle-kit generate`
 - [ ] 2.5 `[opus]` Create data migration script (`scripts/migrate-users.ts`): create default admin user, backfill `user_id` on all existing rows, alter columns to NOT NULL
 
diff --git a/src/lib/db/schema.ts b/src/lib/db/schema.ts
index 5aad160..7fe10d0 100644
--- a/src/lib/db/schema.ts
+++ b/src/lib/db/schema.ts
@@ -16,9 +16,11 @@ export const users = pgTable('users', {
 export const charts = pgTable('charts', {
   id: serial('id').primaryKey(),
   user_id: uuid('user_id').references(() => users.id), // nullable for now; will be NOT NULL after data migration (task 2.5)
-  name: text('name').notNull().unique(),
+  name: text('name').notNull(),
   created_at: timestamp('created_at').notNull().defaultNow(),
-});
+}, (table) => [
+  uniqueIndex('charts_user_id_name_unique').on(table.user_id, table.name),
+]);
 
 export const candles = pgTable('candles', {
   id: serial('id').primaryKey(),
@@ -35,14 +37,16 @@ export const candles = pgTable('candles', {
 export const annotationTypes = pgTable('annotation_types', {
   id: serial('id').primaryKey(),
   user_id: uuid('user_id').references(() => users.id), // nullable for now; will be NOT NULL after data migration (task 2.5)
-  name: text('name').notNull().unique(), // internal name (e.g., 'break_up')
+  name: text('name').notNull(), // internal name (e.g., 'break_up')
   display_name: text('display_name').notNull(), // display name (e.g., 'Break Up')
   color: text('color').notNull(), // hex color code
   category: text('category').notNull(), // 'marker' or 'line'
   icon: text('icon'), // icon name or symbol
   is_active: boolean('is_active').notNull().default(true), // true = active, false = inactive
   created_at: timestamp('created_at').notNull().defaultNow(),
-});
+}, (table) => [
+  uniqueIndex('annotation_types_user_id_name_unique').on(table.user_id, table.name),
+]);
 
 export const annotations = pgTable('annotations', {
   id: serial('id').primaryKey(),
@@ -58,14 +62,16 @@ export const annotations = pgTable('annotations', {
 export const spanLabelTypes = pgTable('span_label_types', {
   id: serial('id').primaryKey(),
   user_id: uuid('user_id').references(() => users.id), // nullable for now; will be NOT NULL after data migration (task 2.5)
-  name: text('name').notNull().unique(), // internal name (e.g., 'bull_flag')
+  name: text('name').notNull(), // internal name (e.g., 'bull_flag')
   display_name: text('display_name').notNull(), // UI label (e.g., 'Bull Flag')
   color: text('color').notNull(), // hex color for rectangle fill
   hotkey: text('hotkey'), // keyboard shortcut (e.g., '1')
   is_active: boolean('is_active').notNull().default(true), // true = active, false = inactive
   sort_order: integer('sort_order').notNull().default(0), // display order
   created_at: timestamp('created_at').notNull().defaultNow(),
-});
+}, (table) => [
+  uniqueIndex('span_label_types_user_id_name_unique').on(table.user_id, table.name),
+]);
 
 export const spanAnnotations = pgTable('span_annotations', {
   id: serial('id').primaryKey(),