Phase3 Backlog Ralph

Autonomously work through a backlog / task list, implementing tasks with commits and review. Use when the user asks to "implement the backlog", "work through the tasks", run a long autonomous build loop, or "/loop"-style continuous task execution. An orchestrator loop: dependency-ordered task selection, one heavily-onboarded implementer subagent per task, a TIERED review gate (lightweight for feature cycles, deep multi-reviewer only for irreversible surfaces and scheduled checkpoints), functionality-first velocity with hardening deferred to a wave against stabilized surfaces, strict honest-failure discipline, and the tracker as durable state. Generalises the "Ralph" agent…