AI Suggest stepper for todos: signal-key driven UI state (aiStep/aiPending) and an AIPhase stepper field on todo.Signals, with SSE progress streaming and LLM integration plumbing in internal/llm.
Fixed
Build: correct AiPhase -> AIPhase struct-literal field on todo.Signals.
CI lint: extract retrySignalFields/retryToastMessage helpers to bring streamRetry cyclomatic complexity under the gocyclo limit; gofumpt-format signal_keys.go.