AddTask, planning CreateChildTask, and SuggestImprovement now accept an
optional alias-validated model (haiku/sonnet/opus; blank = inherit) so the
model is chosen at creation time instead of a follow-up set_task_config call.
The planning, system, and improvement prompts instruct Claude to pick the
cheapest capable model (haiku < sonnet < opus).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Introduces ~/.todo-app/prompts/{system,planning,agent}.md as the canonical
location for prompt content. The settings modal exposes "Open in editor"
shortcuts for each, and TaskRunner merges system.md (always) and agent.md
(for "agent"-tagged tasks) into the effective system prompt alongside the
existing global/list/task layers.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>