Subtasks need inline completion instructions for Haiku agent

[mmorris35]

Problem

The completion marking instructions (how to check off subtasks when done) are currently only in CLAUDE.md. Since the Haiku agent can only concentrate on what's immediately in front of it, it doesn't follow these instructions.

Current Behavior

• Completion instructions live in CLAUDE.md
• Haiku agent executes subtasks from DEVELOPMENT_PLAN.md
• Agent doesn't read linked documents or remember external instructions
• Subtasks don't get marked complete

Expected Behavior

Each subtask should include inline completion instructions, e.g.:

- [ ] **1.1** Implement feature X
  - Do the thing
  - Test the thing
  - ✅ When done: Check this box by changing `- [ ]` to `- [x]`

Solution

Modify subtask generation in src/generators.ts or src/templates.ts to append completion instructions to each subtask.

Labels

bug, haiku-compat