04-add-crud.md

Before implementing, review 00-project-architecture.md and use it as the architecture baseline. Follow it by default, deviate only when necessary.

Task 04: Implement Gantt CRUD persistence via data.save.

Scope:

• task create
• task update
• task delete
• link create
• link delete

Rules:

• React state as the source of truth
• Supabase is the persistence layer
• Persist task ordering
• Use the real UUID returned by Supabase after insert and replace any temporary Gantt id
• Use stable local date conversion helpers
• Persist sortorder as the canonical task ordering field
• Load tasks ordered by sortorder
• Normal task updates must preserve the current sortorder unless a dedicated row-reorder flow changes it
• In this step, prepare task persistence so later row reorder can update sortorder without changing the CRUD architecture
• Build Supabase write payloads from the normalized local task model, not directly from the raw data.save payload
• Persist parent_id only if task.parent is a real UUID
• Do not reject valid project UUIDs with overly strict client-side validation
• Persist a link only when both linked tasks already have real persisted UUIDs
• Build optimistic updates from the latest current task and link state, not from stale render-time state

Append to build-log.md the full request and full response after completion (append only, do not modify existing entries).