feat: personal/work area toggle

Global lens in the home header: every list, Today, Projects and Review
show only the active area; new rows are born into it. Tasks and projects
gain an area column (personal default); the task form's Area chip
re-files across areas.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SW5iVXkZ2JBHgyweMCRymY

server/schema.sql

@@ -38,3 +38,10 @@ create index if not exists tasks_project_idx on tasks (project_id);
 -- Columns added after the initial deploy (create-if-not-exists won't alter).
 alter table tasks add column if not exists repeat text
     check (repeat in ('daily', 'weekdays', 'weekly', 'monthly', 'yearly'));
+
+-- Personal vs work: the app's top-level toggle filters every list by area.
+alter table tasks add column if not exists area text not null default 'personal'
+    check (area in ('personal', 'work'));
+alter table projects add column if not exists area text not null default 'personal'
+    check (area in ('personal', 'work'));
+create index if not exists tasks_area_idx on tasks (area);