feat: add 5 PM features — custom statuses, Gantt, quick-add, automations, notifications

- Custom workflow statuses: per-project configurable status definitions
  replacing the fixed task_status enum. Each project defines its own
  workflow with drag-to-reorder, color coding, and category mapping.
- Gantt/timeline view: full project roadmap with task bars, dependency
  arrows, milestone diamonds, zoom levels (day/week/month), and drag
  to reschedule.
- Natural-language quick-add: NLP parser extracts dates, priorities,
  projects, labels, and recurrence from free text. Floating bar with
  'n' shortcut and live parsed preview.
- Automation rules: no-code trigger-action system per project. Triggers
  on status change, task creation, due date approaching. Actions set
  status/priority, add labels, create notifications.
- Notification center: in-app bell icon with unread badge, slide-out
  panel, real-time SSE updates, mark read/all read. Replaces raw
  activity feed dropdown.

Schema: adds status_definitions, automation_rules, notifications tables.
Migrations: 0007, 0008, 0009. 41 NLP parser tests pass.

package.json

@@ -19,6 +19,7 @@
     "db:generate": "drizzle-kit generate",
     "db:sync": "drizzle-kit push --force",
     "db:triggers": "bun script/apply-triggers.ts",
+    "db:statuses": "bun script/migrate-task-statuses.ts",
     "db:migrate": "bun run db:sync && bun run db:triggers",
     "deploy": "bash script/deploy.sh"
   },