mir-backend-beam-phoenix

Make It Right (Phoenix module). Phoenix + LiveView + Ecto + PostgreSQL specific reliability augmentation. Use alongside mir-backend and mir-backend-beam when the target stack is Phoenix — it carries the mechanical footguns that the framework-agnostic tiers deliberately omit: LiveView per-connection process memory scaling and temporary_assigns/streams for large collections, blocking the LiveView process in handle_event freezing the client, Ecto N+1 with unloaded associations raising DetachedInstanceError, migration safety on populated tables (create index concurrently, disable_ddl_transaction!, expand/contract for NOT NULL), PubSub fan-out backpressure, and idempotent handle_event for double-click races. TRIGGER only when the BEAM backend stack is Phoenix — building, reviewing, or debugging a Phoenix controller, LiveView, Ecto query, or migration. Always loads TOGETHER WITH mir-backend (the gates) and mir-backend-beam (BEAM runtime concerns: supervision, mailbox growth, GenServer bottlenecks, ETS, distributed Erlang); this module only adds Phoenix/Ecto library mechanics. SKIP for plain Erlang/OTP apps, Nerves, or any non-Phoenix stack (those get their own mir-backend-beam-<framework> module), and for non-BEAM runtimes.