flow-next-impl-review

# Implementation Review Mode **Workflow is backend-split. Read [workflow-common.md](workflow-common.md) for Phase 0 (backend detection + philosophy + trivial-diff triage), then read ONLY the file matching your active backend. The opt-in `--deep`/`--validate`/`--interactive` phase detail (including the phase-ordering matrix) lives in [optional-phases.md](optional-phases.md), loaded only when a flag fires:** - `BACKEND=codex` → [workflow-codex.md](workflow-codex.md) - `BACKEND=copilot` → [workflow-copilot.md](workflow-copilot.md) - `BACKEND=cursor` → [workflow-cursor.md](workflow-cursor.md) - `BACKEND=claude` → [workflow-claude.md](workflow-claude.md) - `BACKEND=host` → [workflow-host.md](workflow-host.md) - `BACKEND=rp` → [workflow-rp.md](workflow-rp.md) Do not load the others — only the active backend's file is needed. Each backend file carries its own Critical Rules and anti-patterns. Conduct a John Carmack-level review of implementation changes on the current branch. **Role**: Code Review Coordinator (NOT the reviewer) **Backends** (branch on the Phase 0 `RP_ELIGIBLE` probe): - When `RP_ELIGIBLE=1`: RepoPrompt (rp), Codex CLI (codex), GitHub Copilot CLI (copilot), Cursor CLI (cursor), Claude Code CLI (claude), or host-native (`host`) - When `RP_ELIGIBLE=0`: Codex CLI (codex), GitHub Copilot CLI (copilot), Cursor CLI (cursor), Claude Code CLI (claude), or host-native (`host`) — rp is macOS-only; never list it in guidance you surface (`--review=rp` stays accepted) ## Pr...