fix(todo): use TEXT for user_id columns (Better Auth compatibility)

Better Auth generates non-UUID user IDs (e.g., otUe1YrfENPdHnrF3g1vSBfpkQfambCZ).
Changed all user_id columns from uuid to text type to prevent
"invalid input syntax for type uuid" errors.

Also documented this requirement in:
- .claude/guidelines/authentication.md (new User ID Format section)
- .claude/guidelines/database.md (User ID Column Type section)
- apps/todo/CLAUDE.md (Database Schema section)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

apps/todo/CLAUDE.md

@@ -156,9 +156,11 @@ pnpm preview                     # Preview build
 
 ## Database Schema
 
+> **Note**: `user_id` columns use TEXT type (not UUID) because Mana Core Auth generates non-UUID user IDs.
+
 ### projects
 - `id` (UUID) - Primary key
-- `user_id` (UUID) - Owner
+- `user_id` (TEXT) - Owner (Better Auth format)
 - `name` (VARCHAR) - Project name
 - `color` (VARCHAR) - Hex color
 - `icon` (VARCHAR) - Icon name
@@ -169,7 +171,7 @@ pnpm preview                     # Preview build
 ### tasks
 - `id` (UUID) - Primary key
 - `project_id` (UUID) - FK to projects (nullable = Inbox)
-- `user_id` (UUID) - Owner
+- `user_id` (TEXT) - Owner (Better Auth format)
 - `title` (VARCHAR) - Task title
 - `description` (TEXT) - Description
 - `due_date` (TIMESTAMP) - Due date
@@ -182,7 +184,7 @@ pnpm preview                     # Preview build
 
 ### labels
 - `id` (UUID) - Primary key
-- `user_id` (UUID) - Owner
+- `user_id` (TEXT) - Owner (Better Auth format)
 - `name` (VARCHAR) - Label name
 - `color` (VARCHAR) - Hex color
 
@@ -193,6 +195,7 @@ pnpm preview                     # Preview build
 ### reminders
 - `id` (UUID) - Primary key
 - `task_id` (UUID) - FK to tasks
+- `user_id` (TEXT) - Owner (Better Auth format)
 - `minutes_before` (INTEGER) - Offset
 - `type` (VARCHAR) - push/email/both
 - `status` (VARCHAR) - pending/sent/failed

apps/todo/apps/backend/src/db/schema/kanban-boards.schema.ts

@@ -1,11 +1,20 @@
-import { pgTable, uuid, timestamp, varchar, boolean, integer, index } from 'drizzle-orm/pg-core';
+import {
+	pgTable,
+	uuid,
+	text,
+	timestamp,
+	varchar,
+	boolean,
+	integer,
+	index,
+} from 'drizzle-orm/pg-core';
 import { projects } from './projects.schema';
 
 export const kanbanBoards = pgTable(
 	'kanban_boards',
 	{
 		id: uuid('id').primaryKey().defaultRandom(),
-		userId: uuid('user_id').notNull(),
+		userId: text('user_id').notNull(),
 		projectId: uuid('project_id').references(() => projects.id, { onDelete: 'cascade' }),
 
 		// Board properties

apps/todo/apps/backend/src/db/schema/kanban-columns.schema.ts

@@ -1,4 +1,13 @@
-import { pgTable, uuid, timestamp, varchar, boolean, integer, index } from 'drizzle-orm/pg-core';
+import {
+	pgTable,
+	uuid,
+	text,
+	timestamp,
+	varchar,
+	boolean,
+	integer,
+	index,
+} from 'drizzle-orm/pg-core';
 import { kanbanBoards } from './kanban-boards.schema';
 
 // Define locally to avoid circular dependency with tasks.schema
@@ -8,7 +17,7 @@ export const kanbanColumns = pgTable(
 	'kanban_columns',
 	{
 		id: uuid('id').primaryKey().defaultRandom(),
-		userId: uuid('user_id').notNull(),
+		userId: text('user_id').notNull(),
 		boardId: uuid('board_id')
 			.references(() => kanbanBoards.id, { onDelete: 'cascade' })
 			.notNull(),

apps/todo/apps/backend/src/db/schema/labels.schema.ts

@@ -1,10 +1,10 @@
-import { pgTable, uuid, timestamp, varchar, index } from 'drizzle-orm/pg-core';
+import { pgTable, uuid, text, timestamp, varchar, index } from 'drizzle-orm/pg-core';
 
 export const labels = pgTable(
 	'labels',
 	{
 		id: uuid('id').primaryKey().defaultRandom(),
-		userId: uuid('user_id').notNull(),
+		userId: text('user_id').notNull(),
 		name: varchar('name', { length: 100 }).notNull(),
 		color: varchar('color', { length: 7 }).default('#6B7280'),
 		createdAt: timestamp('created_at', { withTimezone: true }).defaultNow().notNull(),

apps/todo/apps/backend/src/db/schema/projects.schema.ts

@@ -21,7 +21,7 @@ export const projects = pgTable(
 	'projects',
 	{
 		id: uuid('id').primaryKey().defaultRandom(),
-		userId: uuid('user_id').notNull(),
+		userId: text('user_id').notNull(),
 		name: varchar('name', { length: 255 }).notNull(),
 		description: text('description'),
 		color: varchar('color', { length: 7 }).default('#3B82F6'),

apps/todo/apps/backend/src/db/schema/reminders.schema.ts

@@ -1,4 +1,4 @@
-import { pgTable, uuid, timestamp, varchar, integer, index } from 'drizzle-orm/pg-core';
+import { pgTable, uuid, text, timestamp, varchar, integer, index } from 'drizzle-orm/pg-core';
 import { tasks } from './tasks.schema';
 
 export type ReminderType = 'push' | 'email' | 'both';
@@ -11,7 +11,7 @@ export const reminders = pgTable(
 		taskId: uuid('task_id')
 			.notNull()
 			.references(() => tasks.id, { onDelete: 'cascade' }),
-		userId: uuid('user_id').notNull(),
+		userId: text('user_id').notNull(),
 
 		// Timing
 		minutesBefore: integer('minutes_before').notNull(),

apps/todo/apps/backend/src/db/schema/tasks.schema.ts

@@ -45,7 +45,7 @@ export const tasks = pgTable(
 	{
 		id: uuid('id').primaryKey().defaultRandom(),
 		projectId: uuid('project_id').references(() => projects.id, { onDelete: 'set null' }),
-		userId: uuid('user_id').notNull(),
+		userId: text('user_id').notNull(),
 		parentTaskId: uuid('parent_task_id'),
 
 		// Content