implement - Implementation Stage

Invariants

• Require an approved task document before changing implementation files.
• Treat the task document as the primary scope contract.
• Do not broaden scope without user approval.
• Do not rely on provider-specific model switch commands.
• implement auto is the only automation entry point.
• Update TASKS.md at both transitions (Planned → In Progress on start, In Progress → Testing on finish) and re-read the tracker before handoff to confirm the row moved. A stale tracker blocks downstream and headless sessions.

Runtime adapters may expose this stage as a slash command, menu action, or natural-language skill invocation. The portable stage name is implement.

Argument Handling

• {ID} or {task-name} identifies the task document.
• auto enables the implementation-to-ship automation chain after implementation.
• --tier fast|balanced|deep may override the task document recommendation only if the active runtime supports tier routing.