Add todo list with kanban board view

- todos table with title, description, status (todo/in_progress/done),
  priority (urgent/high/medium/low), optional device link, due date
- List view: sorted by priority, inline edit, click-to-advance status
  circle (empty → blue dot → green check), edit/delete actions
- Kanban board view: three columns, move buttons between statuses,
  priority badges, device links, due dates
- Toggle between List and Board views via URL param
- Optional link to a device for repair-related todos
- Sidebar nav item added

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/lib/constants.ts

@@ -49,6 +49,20 @@ export const DEVICE_LOG_TYPES = [
 
 export type DeviceLogType = (typeof DEVICE_LOG_TYPES)[number];
 
+export const TODO_STATUSES = ['todo', 'in_progress', 'done'] as const;
+export const TODO_STATUS_LABELS: Record<string, string> = {
+	todo: 'To Do',
+	in_progress: 'In Progress',
+	done: 'Done'
+};
+
+export const TODO_PRIORITIES = [
+	{ value: 0, label: 'Urgent', color: 'red' },
+	{ value: 1, label: 'High', color: 'orange' },
+	{ value: 2, label: 'Medium', color: 'blue' },
+	{ value: 3, label: 'Low', color: 'gray' }
+] as const;
+
 export const VOLTAGE_OPTIONS = [
 	'110V AC', '115V AC', '120V AC', '127V AC', '220V AC', '230V AC', '240V AC',
 	'5V DC', '6V DC', '9V DC', '12V DC', '15V DC', '19V DC', '24V DC',